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Angle Encoders
February 2004
Angle encoders with integral bearing for
separate shaft coupling
Angle encoders with integral bearing
and integrated stator coupling
Angle encoders without integral bearing
Information about
Rotary Encoders
Position Encoders for Servo Drives
Exposed Linear Encoders
Sealed Linear Encoders
HEIDENHAIN Subsequent Electronics
HEIDENHAIN Controls
are available upon request or on the
Internet under www.heidenhain.de.
This catalog supersedes all previous
editions, which thereby become invalid.
The basis for ordering from HEIDENHAIN
is always the catalog edition valid when
the contract is made.
Standards (ISO, EN, etc.) apply only where
explicitly stated in the catalog.
Contents
Overview
HEIDENHAIN Angle Encoders 4
Selection Guide Angle encoders with integral bearing 6
Angle encoders without integral bearing 8
Technical Characteristics and Mounting Information
Measuring Principles Measuring standard, absolute measuring principle,
incremental measuring principle
10
Scanning the Measuring Standard 12
Measuring Accuracy 14
Mechanical Design
Types and Mounting
RON, RPN, RCN 18
ROD 20
ERP, ERA 180, ERM, ERO 22
ERA 700, ERA 800 24
General Mechanical Information 26
Specifications Series or Model Accuracy
Angle Encoders with
Integral Bearing and
Integrated Stator
Coupling
RON/RCN 200 series ± 5"/± 2.5" 28
RON 785 ± 2" 30
RON/RCN 700 series ± 2" 32
RON/RPN/RCN 800 series ± 1" 34
RON 905 ± 0.4" 36
Angle Encoders with
Integral Bearing for
Separate Shaft Coupling
ROD 200 series ± 5" 38
ROD 780 ± 2" 40
ROD 880 ± 1" 40
Angle Encoders without
Integral Bearing
ERP 880 ± 1" 42
ERA 180 series to ± 3.5" 44
ERM 280 series to ± 11" 48
ERO 785 series to ± 2.5" 50
ERA 700 series to ± 3.2" 52
ERA 800 series to ± 3.4" 54
Electrical Connections
Interfaces and
Pin Layouts
Incremental signals 1 VPP 58
Incremental signals TTL 60
EnDat absolute position values 62
Connecting Elements and Cables 67
General Electrical Specifications 70
Evaluation and Display Units
Display Units, Interpolation and Digitizing Electronics Interface Cards,
HEIDENHAIN Measuring Equipment
72
4
HEIDENHAIN Angle Encoders
The term angle encoder is typically used to
describe encoders that have an accuracy of
better than ± 5" and a line count above
10000.
In contrast, rotary encoders are encoders
that typically have an accuracy of more than
± 10".
Angle encoders are found in applications
requiring precision angular measurement to
accuracies within several arc seconds.
Examples:
Rotary tables on machine tools
Swivel heads on machine tools
C-axes of lathes
Measuring machines for gears
Printing units of printing machines
Spectrometers
Telescopes
etc.
The tables on the following pages list
different types of angle encoders to suit the
various applications and meet different
requirements.
Angle encoders can have one of three
different mechanical designs:
Angle encoders with integral bearing,
hollow shaft and integrated stator
coupling
Because of the design and mounting of the
stator coupling, it must only absorb that
torque caused by friction in the bearing
during angular acceleration of the shaft. RON,
RPN and RCN angle encoders therefore
provide excellent dynamic performance.
With an integrated stator coupling, the
stated system accuracy also includes the
deviations from the shaft coupling.
Other advantages:
Compact size for limited installation space
Hollow shaft diameters up to 60 mm for
leading power cables, etc.
Simple installation
Selection Guide on pages 6/7
The RON 886 angle encoder mounted onto the rotary table of a machine
tool
RON 886
Rotary table
RON 886 incremental angle encoder
5
ROD 800 incremental angle encoder with K 16 flat coupling
Angle encoders with integral bearing,
for separate shaft coupling
ROD angle encoders with solid shaft are
particularly suited to applications where
higher shaft speeds and larger mounting
tolerances are required. The shaft couplings
allow axial tolerances of ± 1 mm.
Selection Guide on pages 6/7
Angle encoders without integral bearing
The ERP, ERO and ERA angle encoders
without integral bearing (modular angle
encoders) are intended for integration in
machine elements or apparatuses. They
are designed to meet the following
requirements:
Large hollow shaft diameter (up to 10 m
with a scale tape)
High shaft speeds up to 40000 rpm
No additional starting torque from shaft
seals
Segment angles
The ERM modular magnetic encoder is
particularly suited to applications with lower
accuracy requirements, such as the C axis
on lathes or auxiliary axes.
Selection Guide on pages 8/9
ERA 180 incremental angle encoder
Overview
6
Selection Guide
Angle Encoders with Integral Bearing
Series System accuracy and
line count
Recommended measuring step/
absolute positions/rev.
Overall dimensions
in mm
Max. mechanically
permissible speed
With integral stator coupling
RON 200
Incremental
± 5" with 18000 0.0001° 3000 rpm
5-fold interpolation0.001°
10-fold interpolation0.0005°
± 5" with 9000 0.005°
± 2.5" with 18000 0.0001°
RCN 200
Absolute
± 5"/± 2.5" with 16384 0.0001°
26 bits 67108 864 positions/rev.
RON 700
Incremental
± 2" with 18000 0.0001° 1000 rpm
± 2" with 18000
± 2" with 36000
0.0001° 1000 rpm
RCN 700
Absolute
± 2" with 32768 0.0001°
27 bits 134 217728 positions/rev.
RON 800
Incremental
± 1" with 36000 0.00005° 1000 rpm
RPN 800
Incremental
± 1" with 90000
(180000 signal periods)
0.00001°
RCN 800
Absolute
± 1" with 32768 0.0001°
27 bits 134 217728 positions/rev.
RON 900
Incremental
± 0.4" with 36000 0.00001° 100 rpm
For separate shaft coupling
ROD 200
Incremental
± 5" with 18000 0.0001°
ROD 260:0.005°
ROD 270:0.0005°
10000 rpm
ROD 700
Incremental
± 2" with 18000
± 2" with 36000
0.0001° 1000 rpm
ROD 800
Incremental
± 1" with 36000 0.00005°
7
Incremental signals/
data interface
Reference marks Model See
page
1 VPP One or
distance-coded
RON 285 28
TTL x 5/10
5/10-fold interpolation
One RON 275
TTL x 2 (1 MHz)
2-fold interpolation
One RON 225
1 VPP One or
distance-coded
RON 287
1 VPP
EnDat
– RCN 226
1 VPP One or
distance-coded
RON 785 30
1 VPP One or
distance-coded
RON 786 32
1 VPP
EnDat
– RCN 727
1 VPP One or
distance-coded
RON 886 34
One RPN 886
– RCN 827
11 µAPP One RON 905 36
1 VPP One or
distance-coded
ROD 280 38
TTL (1 MHz) One ROD 260
TTL
10-fold interpolation
One ROD 270
1 VPP One or
distance-coded
ROD 780 40
1 VPP One or
distance-coded
ROD 880 40
RON 285
ROD 285
RON 786
ROD 780
RON 905
8
Selection Guide
Angle Encoders without Integral Bearing
Series Line count/
System accuracy1)
Recommended
measuring step
Overall dimensions
in mm
Diameter
D1/D2
Max. mech.
permissible
speed
Grating on solid scale carrier
ERP 880
Glass disk with
interferential
grating
90000/± 1" 1)
(180000 signal
periods)
0.00001° – 1000 rpm
ERA 180
Steel drum
with axial
grating
6000/± 7.5" to
36000/± 2.5" 1)
0.0015° to
0.0001°
D1: 40 to 512 mm
D2: 80 to 562 mm
40000 rpm to
6000 rpm
ERM 200
Steel drum
with magnetic
grating
600/± 36" to
2600/± 10" 1)
0.003° to 0.001° D1: 40 to 295 mm
D2: 75.44 to
326.9 mm
24000 rpm to
5000 rpm
as of mid-2004:
40000 rpm to
7000 rpm
ERO 785
Glass disk with
radial grating
36000/± 4.2" to
± 2.2" 1)
0.0001° D1: 47 mm
D2: 129.9 mm
8000 rpm
D1: 102 mm
D2: 182 mm
6000 rpm
D1: 155.1 mm
D2: 256.9 mm
4000 rpm
Grating on steel tape
ERA 700
For inside
diameter
mounting
Full circle1)
36000/± 3.5"
45000/± 3.4"
90000/± 3.2"
0.0001° to
0.00002°
458.62 mm
573.20 mm
1146.10 mm
500 rpm
Segment2)
5000
10000
20000
318.58 mm
458.62 mm
573.20 mm
ERA 800
For outside
diameter
mounting
Full circle1)
36000/± 3.5"
45000/± 3.4"
0.0001° to
0.00005°
458.04 mm
572.63 mm
100 rpm
Segment2)
5000
10000
20000
317.99 mm
458.04 mm
572.63 mm
1) Without installation. Additional error caused by mounting inaccuracy
and inaccuracy from the bearing of the measured shaft are not included.
2) Angular segment from 50° to 200°; see Measuring Accuracyfor the
accuracy.
9
ERO 785
ERM 280
ERA 880
Output signals Reference marks Model See
page
1 VPP One ERP 880 42
1 VPP One ERA 180 44
1 VPP One ERM 280 48
1 VPP One ERO 785 50
1 VPP Distance-coded
(nominal increment
of 1000 grating
periods)
ERA 780C full circle 52
ERA 781C segment
1 VPP Distance-coded
(nominal increment
of 1000 grating
periods)
ERA 880C full circle 54
ERA 881C segment
with tensioning elements
ERA882C segment without
tensioning elements
ERA 180
ERP 880
10
Measuring Principles
Measuring Standard
HEIDENHAIN encoders incorporate
measuring standards of periodic structures
known as graduations. These graduations
are applied to a glass or steel substrate.
Glass scales are used primarily in encoders
for speeds up to 10000 rpm. For higher
speeds—up to 40000 rpm—steel drums
are used. The scale substrate for large
diameters is a steel tape.
These precision graduations are manufactured
in various photolithographic
processes. Graduations are fabricated from:
extremely hard chromium lines on glass
or gold-plated steel drums,
matte-etched lines on gold-plated steel
tape, or
three-dimensional structures etched into
quartz glass.
These photolithographic manufacturing
processes—DIADUR and AURODUR—
developed by HEIDENHAIN produce
grating periods of:
40 µm with AURODUR,
10 µm with DIADUR, and
4 µm with etched quartz glass
These processes permit very fine grating
periods and are characterized by a high
definition and homogeneity of the line
edges. Together with the photoelectric
scanning method, this high edge definition
is a precondition for the high quality of the
output signals.
The master graduations are manufactured
by HEIDENHAIN on custom-built highprecision
ruling machines.
Magnetic encoders use a graduation carrier
of magnetizable steel alloy. A graduation
consisting of north poles and south poles is
formed with a grating period of 400 µm
(MAGNODUR process). Due to the short
distance of effect of electromagnetic
interaction, and the very narrow scanning
gaps required, finer magnetic graduations
are not practical.
Absolute encoders feature multiple coded
graduation tracks. The code arrangement
provides the absolute position information,
which is available immediately after
restarting the machine. The track with the
finest grating structure is interpolated for
the position value and at the same time is
used to generate an incremental signal (see
EnDat Interface).
Circular graduations of absolute angle encoders
Absolute Measuring Method
Schematic representation of a circular scale with absolute grating
11
Incremental Measuring Method
With incremental measuring methods,
the graduation consists of a periodic grating
structure. The position information is
obtained by counting the individual
increments (measuring steps) from some
point of origin. Since an absolute reference
is required to ascertain positions, the scales
or scale tapes are provided with an additional
track that bears a reference mark. The
absolute position on the scale, established
by the reference mark, is gated with
exactly one measuring step.
The reference mark must therefore be
scanned to establish an absolute reference
or to find the last selected datum.
In some cases, however, this may require
a rotation up to nearly 360°. To speed and
simplify such “reference runs,” many
encoders feature distance-coded reference
marks—multiple reference marks
that are individually spaced according to a
mathematical algorithm. The subsequent
electronics find the absolute reference after
traversing two successive reference
marks—meaning only a few degrees
traverse (see table).
Encoders with distance-coded reference
marks are identified with a “C” behind the
model designation (e.g. RON 786C).
With distance-coded reference marks, the
absolute reference is calculated by
counting the signal periods between two
reference marks and using the following
formula:
Circular graduations of incremental angle encoders
1 = (abs A–sgn A–1) x I + (sgn A–sgn D) x abs MRR
where:
A = 2 x abs MRR–I
GP
and:
1 = Absolute angular position of the first
traversed reference mark to the
zero position in degrees
abs = Absolute value
sgn = Sign function (“+1” or ”–1”)
MRR = Measured distance between the
traversed reference marks in degrees
I = Nominal increment between two
fixed reference marks (see table)
GP = Grating period (line count)
D = Direction of rotation (+1 or –1)
Rotation to the right (as seen from
the shaft side of the angle
encoder—see Mating Dimensions)
gives “+1”
360°
Line count z Number of
reference marks
Nominal increment I
90000
45000
36000
18000
180
90
72
36
4°
8°
10°
20°
2 2
Distance-coded reference marks on a circular scale
Technical Characteristics and Mounting Info
12
Scanning the Measuring Standard
Photoelectric Scanning
Most HEIDENHAIN encoders operate using
the principle of photoelectric scanning. The
photoelectric scanning of a measuring
standard is contact-free, and therefore
without wear. This method detects even
very fine lines, no more than a few microns
wide, and generates output signals with
very small signal periods.
The finer the grating period of a measuring
standard is, the greater the effect of
diffraction on photoelectric scanning.
HEIDENHAIN uses two scanning principles
with angle encoders:
The imaging scanning principle
for grating periods from 10 µm to
approx. 40 µm.
The interferential scanning principle
for very fine graduations with grating
periods of 4 µm.
Imaging scanning principle
Put simply, the imaging scanning principle
functions by means of projected-light signal
generation: two graduations with equal
grating periods are moved relative to each
other—the scale and the scanning reticle.
The carrier material of the scanning reticle
is transparent, whereas the graduation on
the measuring standard may be applied to
a transparent or reflective surface. When
parallel light passes through a grating, light
and dark surfaces are projected at a certain
distance. An index grating with the same
grating period is located here. When the
two gratings move relative to each other,
the incident light is modulated. If the gaps
in the gratings are aligned, light passes
through. If the lines of one grating coincide
with the gaps of the other, no light passes
through. Photocells convert these
variations in light intensity into nearly
sinusoidal electrical signals. The specially
structured grating of the scanning reticle
filters the light current to generate nearly
sinusoidal output signals.
The smaller the period of the grating
structure is, the closer and more tightly
toleranced the gap must be between the
scanning reticle and circular scale. Practical
LED light source
Measuring standard
Photocells
Condenser lens
Scanning reticle
Imaging scanning principle
mounting tolerances for encoders with the
imaging scanning principle are achieved
with grating periods of 10 µm and larger.
The ROD, RON, RCN, ERA and ERO angle
encoders operate according to the imaging
scanning principle.
Interferential scanning principle
The interferential scanning principle exploits
the diffraction and interference of light on a
fine graduation to produce signals used to
measure displacement. A step grating is
used as the measuring standard: reflective
lines 0.2 µm high are applied to a flat,
reflective surface. In front of that is the
scanning reticle—a transparent phase
grating with the same grating period as the
scale.
When a light wave passes through the
scanning reticle, it is diffracted into three
partial waves of the orders –1, 0, and 1,
with approximately equal luminous intensity.
The waves are diffracted by the scale such
that most of the luminous intensity is found
in the reflected diffraction orders 1 and –1.
These partial waves meet again at the
phase grating of the scanning reticle where
they are diffracted again and interfere. This
Interferential scanning principle (optics schematics)
C Grating period
Phase shift of the light wave when passing through the
scanning reticle
Phase shift of the light wave due to motion x of the scale
LED
light source
Photocells
Condenser lens
Scanning reticle
Measuring standard
I90° and I270°
photocells
not shown
13
Magnetic Scanning
produces essentially three waves that leave
the scanning reticle at different angles.
Photocells convert this alternating light
intensity into electrical signals.
A relative motion of the scanning reticle to
the scale causes the diffracted wave fronts
to undergo a phase shift: when the grating
moves by one period, the wave front of the
first order is displaced by one wavelength
in the positive direction, and the wavelength
of diffraction order –1 is displaced by one
wavelength in the negative direction. Since
the two waves interfere with each other
when exiting the grating, the waves are
shifted relative to each other by two wavelengths.
This results in two signal periods
from the relative motion of just one grating
period.
Interferential encoders function with
average grating periods of 4 µm and finer.
Their scanning signals are largely free of
harmonics and can be highly interpolated.
These encoders are therefore especially
suited for high resolution and high accuracy.
Even so, their generous mounting
tolerances permit installation in a wide
range of applications.
The RPN 886 and ERP 880 angle encoders
operate according to the interferential
scanning principle.
The magnetic scanning principle uses a
measuring standard of hard magnetic metal
carrying a permanently magnetic
MAGNODUR graduation. The graduation is
formed from alternating north and south
poles. The scale is scanned with magnetoresistive
sensors, whose resistance changes
in response to a magnetic field. When a
voltage is applied to the sensor, the flowing
current is modulated according to the
magnetic field.
The special geometric arrangement of the
resistive sensors ensures a high signal
quality, which is a precondition for the
smallest possible deviation within one signal
period. A single magnetized pole pair on a
separate track produces a reference mark
signal. This makes it possible to assign this
absolute position value to exactly one
measuring step.
HEIDENHAIN encoders with magnetic
scanning typically have grating periods of
400 µm. Due to the sensitivity of magnetic
scanning to variations in the scanning gap,
smaller grating periods are very difficult to
produce. Therefore, depending on the
graduation circumference, magnetic
encoders have at most 2600 signal periods
per revolution, and according to the
HEIDENHAIN definition are not angle
encoders.
Magnetoresistive scanning is used primarily
for comparatively low-accuracy applications.
The ERM encoders operate according to
the magnetic scanning principle.
Measuring standard
Scanning
reticle
Magnetoresistive scanning principle
Magnetoresistive sensors for B+ and B– not shown
14
Measuring Accuracy
Position deviation
within one
signal period
Position deviation within one signal period
Position
Signal period
360 °elec.
Position deviations within one revolution
Position deviation
Position deviation Signal levels
error of the coupling must be added (see
Mechanical Design Types and Mounting
—ROD).
For angle encoders without integral
bearing, additional deviations resulting
from mounting, errors in the bearing of
the drive shaft, and adjustment of the
scanning head must be expected (see
Measuring Accuracy—Angle Encoders
without Integral Bearing). These
deviations are not reflected in the system
accuracy.
The system accuracy reflects position
deviations within one revolution as well as
those within one signal period.
Position deviations within one revolution
become apparent in larger angular motions.
Position deviations within one signal
period already become apparent in very
small angular motions and in repeated
measurements. They especially lead to
speed ripples in the speed control loop.
These deviations within a signal period are
caused by the quality of the sinusoidal
scanning signals and their subdivision. The
following factors influence the result:
The size of the signal period,
The homogeneity and edge definition of
the graduation,
The quality of the optical filter structures
on the scanning reticle,
The characteristics of the photoelectric
detectors, and
The stability and dynamics during the
further processing of the analog signals.
HEIDENHAIN angle encoders take these
factors of influence into account, and permit
interpolation of the sinusoidal output signal
with subdivision accuracies of better than
± 1%of the signal period (RPN: ± 1.5%).
The reproducibility is even better, meaning
that useful electric subdivision factors and
small signal periods permit small enough
measuring steps (see Specifications).
Example:
Angle encoder with 36000 sinusoidal signal
periods per revolution
One signal period corresponds to 0.01° or 36".
At a signal quality of ± 1%, this results in
maximum position deviations within one
signal period of approx. ± 0.0001° or ± 0.36".
The accuracy of angular measurement is
mainly determined by:
1. The quality of the graduation
2. The quality of scanning
3. The quality of the signal processing
electronics
4. The eccentricity of the graduation to the
bearing,
5. The radial deviation of the bearing,
6. The elasticity of the encoder shaft and
its coupling with the drive shaft
7. The elasticity of the stator coupling
(RON, RPN, RCN) or shaft coupling
(ROD)
In positioning tasks, the accuracy of the
angular measurement determines the
accuracy of the positioning of a rotary axis.
The system accuracy given in the
Specificationsis defined as follows:
The extreme values of the total deviations
of a position are—referenced to their mean
value—within the system accuracy ± a.
For angle encoders with integral bearing
and integrated stator coupling, this value
also includes the deviation due to the
shaft coupling.
For angle encoders with integral bearing
and separate shaft coupling, the angle
15
For its angle encoders with integral
bearings, HEIDENHAIN prepares individual
calibration charts and ships them with the
encoder.
The calibration chart documents the
encoder’s accuracy and serves as a
traceability record to a calibration standard.
For the RON, RPN and RCN, which feature
an integrated coupling, the accuracy
specifications already include the error of
the coupling. For angle encoders with
separate shaft coupling, however, the error
caused by the coupling is not included in
the encoder specification and must be
added to calculate the total error (see
Kinematic error of transferunder Mechanical
Design Types and Mounting – ROD).
Angle Encoders with Integral Bearing
The manufacturer’s inspection certificate
certifies the accuracy of the encoder. The
calibration standard is indicated in order
to certify the traceability to the national
standard.
The reversal error depends on the shaft
coupling:
For angle encoders with integrated stator
coupling the values are:
RON, RCN 200 0.8"
RON, RPN, RCN 700/800 0.6"
The accuracy of angle encoders is
ascertained through five forward and five
backward measurements. The measuring
positions per revolution are chosen to
determine very exactly not only the longrange
error, but also the position error
within one signal period.
All measured values determined in this
manner lie within or on the graphically
depicted envelope curve. The mean value
curve shows the arithmetic mean of the
measured values, whereby the reversal
error is not included.
Guaranteed accuracy grade of the measured object
Calibration chart example: RON 285
1 Graphic representation of error
Envelope curve
Mean value curve
2 Results of calibration
1
2
16
Measuring Accuracy
Angle Encoders without Integral Bearing
In addition to the system accuracy, the
mounting and adjustment of the scanning
head normally have a significant effect on
the accuracy that can be achieved with
angle encoders without integral bearings.
Of special importance are the mounting
eccentricity and radial runout of the drive
shaft.
To evaluate the accuracy of angle
encoders without integral bearing (ERA,
ERM and ERO), each of the significant
errors must be considered individually.
1. Directional deviations of the graduation
ERA 180, ERM and ERO: The extreme
values of the directional deviation with
respect to their mean value are shown in
the Specificationsas the graduation
accuracy for each model. The graduation
accuracy and the position deviation within
a signal period comprise the system
accuracy.
ERA 700 and ERA 800 series
The extreme values of the directional
deviations depend on
the graduation accuracy,
the irregular scale-tape expansion during
mounting, and
deviations in the scale-tape butt joints
(only for ERA 780C/ERA 880C).
The special graduation manufacturing
process and the butt joints precisely
machined by HEIDENHAIN reduce
directional deviations of the graduation
to within 3 to 5 angular seconds (with
accurate mounting).
2. Error due to eccentricity of the
graduation to the bearing
Under normal circumstances the bearing
will have a certain amount of radial runout
or shape deformation after the disk/hub
assembly (ERO), circumferential-scale drum
(ERA 180, ERM), or scale tape (ERA 78xC
and ERA 88xC) is mounted. When centering
using the centering collar of the hub or the
drum, please note that HEIDENHAIN
guarantees an eccentricity of the graduation
to the centering collar of under 1 µm. For
the modular angle encoders, this accuracy
value presupposes a diameter deviation of
zero between the encoder shaft and the
“master shaft.” If the centering collar is
centered on the bearing, then in a
worst-case situation both eccentricity
vectors could be added together.
The following relationship exists between
the eccentricity e,the mean graduation
diameter Dand the measuring error
(see illustration below):
= ± 412 ·
e
D
= Measuring error in seconds of arc
e = Eccentricity of the radial grating to the
bearing in µm
D = Mean graduation diameter (ERO) or
drum outside diameter (ERA 180,
ERM) and scale tape mount diameter
(ERA 78xC/ERA 88xC) in millimeters
M = Center of graduation
= “True” angle
‘ = Scanned angle
ERA 781C, ERA 881C, ERA 882C
In these segment solutions, the additional
angular error occurs when the nominal
scale-tape bearing-surface diameter is not
exactly maintained:
= (1 – D’/D) · · 3600
where
= Segment deviation in angular seconds
= Segment angle in degrees
D = Nominal scale-tape carrier diameter
D’ = Actual scale-tape carrier diameter
This error can be eliminated if the line count
per 360° valid for the actual scale-tape
carrier diameter D’ can be entered in the
control. The following relationship is valid:
z’ = z · D’/D
where z = Nominal line count per 360°
z’ = Actual line count per 360°
The angle actually traversed in individual
segment solutions should be measured
with a comparative encoder, such as an
angle encoder with integral bearing.
Angular error due to variations in scale-tape carrier diameter
Eccentricity of the graduation to the bearing
Scanning unit
Segment
Segment version
Center of graduation
17
4. Position error within one signal period
u
The scanning units of all HEIDENHAIN
encoders are adjusted so that the maximum
position error values within one signal
period will not exceed the values listed
below, with no further electrical adjusting
required at mounting.
Model Mean
graduation
diameter D
Deviation
per 1 µmof
eccentricity
ERP 880 D = 126 mm ± 3.3"
ERA 180 D = 80 mm
D = 130 mm
D = 180 mm
D = 250 mm
D = 330 mm
D = 485 mm
D = 562 mm
± 5.2"
± 3.2"
± 2.3"
± 1.6"
± 1.2"
± 0.8"
± 0.7"
ERM 280 D = 75 mm
D = 113 mm
D = 130 mm
D = 150 mm
D = 176 mm
D = 260 mm
D = 325 mm
± 5.5"
± 3.6"
± 3.2"
± 2.7"
± 2.3"
± 1.6"
± 1.3"
ERO 785 D = 110 mm
D = 165 mm
D = 240 mm
± 3.7"
± 2.5"
± 1.7"
ERA 78xC D = 320 mm
D = 460 mm
D = 570 mm
D = 1145 mm
± 1.3"
± 0.9"
± 0.7"
± 0.4"
ERA 88xC D = 320 mm
D = 460 mm
D = 570 mm
± 1.3"
± 0.9"
± 0.7"
3. Error due to radial deviation of the
bearing
The equation for the measuring error is
also valid for radial deviation of the bearing
if the value of eis replaced with the
eccentricity value, i.e. half of the radial
deviation (half of the displayed value).
Bearing compliance to radial shaft loading
causes similar errors.
Resultant measured deviations for various eccentricity values e
as a function of mean graduation diameter D
Mean graduation diameter D[mm]
Measured deviations [seconds of arc]
Model Line count Position error
within one signal
period u
ERP 880 90000 ± 0.15"
ERA 180 36000
18000
9000
6000
± 0.5"
± 1"
± 2"
± 2.5"
ERM 280 2600
2048
1400
1200
1024
900
600
± 6"
± 7"
± 11"
± 12"
± 13"
± 15"
± 22"
ERO 785 36000 ± 0.5"
ERA 78xC,
ERA 88xC
90000
45000
36000
± 0.2"
± 0.4"
± 0.5"
The values for the position errors within
one signal period are already included in the
system accuracy. Larger errors can occur if
the mounting tolerances are exceeded.
18
Mechanical Design Types and Mounting
RON, RPN, RCN
RON, RPN and RCN angle encoders have
an integral bearing, hollow shaft and
integrated stator coupling. The measured
shaft is directly connected with the shaft of
the angle encoder. The reference mark can
be assigned to a desired angular position of
the measured shaft from the rear of the
encoder during mounting.
The graduated disk is rigidly affixed to the
hollow shaft. The scanning unit rides on the
shaft on ball bearings and is connected to
the housing with a coupling on the stator
side. During angular acceleration of the shaft,
the coupling must absorb only that torque
caused by friction in the bearing. Angle
encoders with integrated stator coupling
therefore provide excellent dynamic
performance.
Mounting
The housing of the RON, RPN and RCN is
firmly connected to the stationary machine
part with an integral mounting flange and a
centering collar. Liquids can easily flow
away through drainage channels on the
flange.
Shaft coupling with ring nut
The RON, RPN and RCN series have a
hollow through shaft. For installation, the
hollow through shaft of the angle encoder
is placed over the machine shaft, and is
fixed with a ring nut from the front of the
encoder.
RON 905 shaft coupling
The RON 905 has a bottomed hollow shaft.
The shaft connection is made via an axial
central screw.
Front-end shaft coupling
It is often advantageous, especially with
rotary tables, to integrate the angle encoder
in the table so that it is freely accessible
when the rotor is lifted. This installation from
above reduces mounting times, increases
the ease for servicing, and improves the
accuracy, since the encoder is located
nearer to the rotary table bearing and the
measuring or machining plane. The hollow
shaft is attached with the threaded holes
on the face, using special mounting
elements fitted to the individual design (not
included in delivery).
To comply with radial and axial runout
specifications, the internal hole and the
shoulder surface are to be used as
mounting surfaces for shaft coupling at the
face of the encoder.
Front-end shaft coupling with RON 786
Customized version
Rotor
RON 786
Stator
Mounting an RON angle encoder with hollow through shaft
Centering collar
Ring nut
Drive shaft
Cross section of the RON 886 angle encoder
Light source
(LED) with
condenser lens Photocells
Hollow shaft
Integrated coupling
DIADUR
graduated disk
19
Ring nut for RON/RCN 200
Id. Nr. 336669-03
Ring nut for RON 785
Id. Nr. 336669-05
Ring nut for RON 786
RON/RPN 886
RCN 727/RCN 827
Id. Nr. 336669-01
Ring nuts for RON, RPN and RCN
HEIDENHAIN offers special ring nuts for
the RON, RPN and RCN angle encoders
with integral bearing and hollow through
shaft with integrated coupling. Choose the
tolerance of the shaft thread such that the
ring nut can be tightened easily, with a
minor axial play. This guarantees that the
load is evenly distributed on the shaft
connection, and prevents distortion of the
hollow shaft of the angle encoder.
L1 L2 D1 Thread
diameter D2
D3
RON 785 62±0.2 55 ( 49.052
±0.075)
49.469
±0.059
( 50.06)
RON 786
RON/RPN 886
RCN 727/RCN 827
70±0.2 65 ( 59.052
±0.075)
59.469
±0.059
( 60.06)
*) Thread diameter
20
Angle encoders of the ROD product family
require a separate coupling for connection
to the drive shaft. The shaft coupling compensates
axial movement and misalignment
between the shafts, preventing excessive
load on the encoder bearing of the angle
encoder. It is important that the encoder
shaft and the drive shaft be optimally aligned
for high measurement accuracies to be
realized. The HEIDENHAIN product program
includes diaphragm couplings and flat
couplings designed for connecting the shaft
of the ROD angle encoder to the drive shaft.
Mounting
ROD angle encoders are provided with an
integral mounting flange with centering
collar. The encoder shaft is connected to
the drive shaft by way of a diaphragm
coupling or flat coupling.
Shaft couplings
The shaft coupling compensates axial
movement and misalignment between the
encoder shaft and the drive shaft, preventing
excessive load on the encoder bearing of
the angle encoder.
Radial misalignment
Angular error
Axial motion
Mounting
example
ROD 880
Rotary
table
ROD 880
Additional
protection
against fluids
Shaft
coupling
Mounting
an ROD
ROD
Centering collar
Flat coupling
Mechanical Design Types and Mounting
ROD
ROD 200 Series ROD 700 Series, ROD 800 Series
Shaft coupling K 03
Diaphragm coupling
K 18
Flat coupling
K 01
Diaphragm coupling
K 15
Flat coupling
K 16
Flat coupling
Hub bore 10 mm 14 mm
Kinematic transfer error ± 2" ± 3" ± 1" ± 0.5"
at 0.05 mm and 0.03° at 0.1 mm and 0.09°
Torsional rigidity 1500 Nm/rad 1200 Nm/rad 4000 Nm/rad 6000 Nm/rad 4000
Nm/rad
Permissible torque 0.2 Nm 0.5 Nm
Permissible radial offset 0.3 mm
Permissible angular error 0.5° 0.2° 0.5°
Permissible axial offset 0.2 mm 0.1 mm 1mm
Moment of inertia (approx.) 20 · 10–6 kgm2 75 · 10–6 kgm2 200 · 10–6
kgm2 400 ·10–6 kgm2
Permissible speed 10000 rpm 1000 rpm 3000 rpm 1000 rpm
Torque for locking screws
(approx.)
1.2 Nm 2.5 Nm 1.2 Nm
Weight 100 g (0.22 lb) 117 g (0.258 lb) 180 g (0.4 lb) 250 g (0.55 lb)
410 g (0.9 lb)
21
K 03 diaphragm coupling
Id. Nr. 200313-04
K 18 flat coupling
Id. Nr. 202227-01
K 01 diaphragm coupling
Id. Nr. 200301-02
K 16 flat coupling
Id. Nr. 258878-01
K 15 flat coupling
Id. Nr. 255797-01
Dimensions in mm
22
Mechanical Design Types and Mounting
ERP
The ERP 880 modular angle encoder
consists of the following components:
scanning unit, disk/hub assembly, and PCB.
Cover caps for protection from contact or
contamination can be supplied as
accessories.
Mounting—ERP
First the scanning unit is mounted on the
stationary machine part with an alignment
of ± 1.5 µm to the shaft. Then the front
side of the disk/hub assembly is screwed
onto the shaft, and is also aligned with a
maximum eccentricity of ± 1.5 µm to the
scanning unit. Then the PCB is attached
and connected to the scanning unit. Fine
adjustment takes place by “electrical
centering” using the PWM 9 (see
HEIDENHAIN Measuring Equipment) and
an oscilloscope. The ERP 880 can be
protected from contamination by covering
it with a cap.
Mounting the
ERP 880
(in principle)
IP 40 cover cap
With sealing ring for IP 40 protection
Cable 1 m with male coupling, 12-pin
Id. Nr. 369774-01
IP 64 cover cap
With shaft seal for IP 64 protection
Cable 1 m with male coupling, 12-pin
Id. Nr. 369774-02
23
ERA 180, ERM, ERO
The ERA 180, ERM and ERO modular
angle encoders consist of either a
circumferential-scale drum (ERA, ERM)
or a disk/hub assembly (ERO) and the
corresponding scanning unit. Special design
features of the modular angular encoders
assure comparably fast mounting and easy
adjustment.
Mounting—ERA 180, ERM
The circumferential-scale drum is slid onto
the drive shaft and fastened with screws.
HEIDENHAIN recommends using a
transition fit for mounting the scale drum.
For mounting, the scale drum may be slowly
warmed on a heating plate over a period of
approx. 10 minutes to a temperature of
max. 100 °C. The scale drum is centered via
the centering collar on its inner circumference.
The scanning unit is mounted with
the spacer foil attached to the circumferentialscale
drum. The scanning unit is pressed
against the foil, the screws are tightened,
and the foil is removed.
To protect the ERA 180 from contamination,
HEIDENHAIN supplies a protective cover
for drum diameters up to 180 mm. For
larger diameters, HEIDENHAIN recommends
integrating a protective cover into the
machine itself.
Mounting—ERO
The disk/hub assembly is slid onto the drive
shaft, centered, and fastened with screws.
The scanning unit is then slid onto the
centering collar of the hub and the screws
are tightened. The gap between the
graduated disk and the scanning unit is set
with spacer foils.
Cross
section of
ERO 785
Hub
Graduated disk
Scanning unit
Cross
section of
ERA 180
Scanning unit
Scale drum
Protective cover
Mounting the
ERA 180 and
the ERM 280
(in principle)
24
Mechanical Design Types and Mounting
ERA 700 and ERA 800 Series
The encoders of the ERA 700 and ERA 800
series consist of a scanning unit and a onepiece
steel scale tape up to 30 m in length.
The tape is mounted on the
inside diameter (ERA 700 series) or
outside diameter (ERA 800 series)
of a machine element.
The ERA 780C and ERA 880C angle
encoders are designed for full-circle
applications. Thus, they are particularly
suited to hollow shafts with large inside
diameters (from approx. 300 mm) and to
applications requiring an accurate
measurement over a large circumference,
e.g. large rotary tables, telescopes, etc.
In applications where there is no full circle,
or measurement is not required over 360°,
segment angles are available for
diameters from 300 mm.
Mounting the scale tape for full-circle
applications
ERA 780C: An internal slot with a certain
diameter is required as scale tape carrier.
The tape is inserted starting at the butt joint
and is clicked into the slot. The length is cut
so that the tape is held in place by its own
spring force. To make sure that the scale
tape does not move within the slot, it is
fixed with adhesive at multiple points in the
area of the butt joint.
ERA 880C: The scale tape is supplied with
the halves of the tensioning cleat already
mounted on the tape ends. An external
slot is necessary for mounting. Space must
also be provided for the tensioning cleat.
The tape is placed in the outside slot of the
machine (along slot edge) and is tensioned
using the tensioning cleat. The scale tape
ends are manufactured so exactly that only
minor signal-form deviations can occur in the
area of the butt joint.
Mounting the scale tape for segment
angles
ERA 781C: An internal slot with a certain
diameter is required. Both bearing pieces
are fixed in this slot, and are adjusted with
cam disks so that the scale can be pressed
into the slot while under tension.
Spring
ERA 881C: The scale tape is supplied with
premounted bearing pieces. An external
slot with recesses for the bearing pieces is
required for placing the scale tape. The
scale tape is fitted with tension springs,
which create an optimal bearing preload for
increasing the accuracy of the scale tape,
and evenly distribute the expansion over
the entire length of the scale tape.
ERA 882C: An external slot or one-sided
axial stop is recommended for placing the
scale tape. The scale tape is supplied
without tensioning elements. It must be
preloaded with a spring balance, and fixed
with the two oblong holes.
Cam disks
25
The following must be kept in mind for
segment applications:
Determining the slot diameter
In order to guarantee the correct functioning
of the distance-coded reference
marks, the circumference of the theoretical
full circle must be a multiple of 1000 grating
periods. This also facilitates adaptation to
the NC control, which mostly can only
calculate integer line counts. The connection
between the basic slot diameter and
the line count can be seen in the table.
Segment angles
The measuring range available for the
segment angle should be a multiple of
1000 signal periods, since these versions
are available more quickly.
Mounting the scanning head
A spacer foil is placed against the scale
tape. The scanning head is pushed up
against the spacer foil in such a way that
the foil is only located between the two
mechanical support points on the mounting
bracket. The scanning head is secured in
this position and the foil is removed.
Adjusting the scanning head
Accurate alignment of the scanning head
with the scale tape is critical for the
ERA 700/800 to provide accurate and
reliable measurements (Moiré setting). If
the scanning head is not properly aligned,
the quality of the output signals will be
poor.
The quality of the output signals can be
checked using HEIDENHAIN’s PWT phaseangle
testing unit. When the scanning
head is moved along the scale tape, the
PWT unit graphically displays the quality of
the signals as well as the position of the
reference mark. The PWM 9 phase angle
measuring unit calculates a quantitative
value for the deviation of the actual output
signals from the ideal signal (see
HEIDENHAIN Measuring Equipment).
Basic slot diameter Line count projected onto a
full circle
ERA 781C 318.58 + n · 12.73111 25000 + n · 1000
ERA 881C/
ERA 882C
317.99 + n · 12.73178 25000 + n · 1000
Measuring range
Theoretical full circle
Basic slot diameter
PWT
Spacer foil
26
Protection
Unless otherwise indicated, all RON, RPN,
RCN and ROD angle encoders meet protection
standard IP 67 according to IEC 60529.
This includes housings and cable outlets.
The shaft inlet provides protection to IP 64.
Splash water should not contain any
substances that would have harmful effects
on the encoder parts. If protection to IP 64
of the shaft inlet is not sufficient (such as
when the angle encoder is mounted
vertically), additional labyrinth seals should
be provided.
RON, RPN, RCN and ROD angle encoders
are equipped with a compressed air inlet.
Connection to a source of compressed air
slightly above atmospheric pressure
provides additional protection against
contamination.
General Mechanical Information
Temperature range
The operating temperature range
indicates the limits of ambient temperature
within which the values given in the specifications
for angle encoders are maintained
(DIN 32878).
The storage temperature range of –30 to
+80 °C (–22 to +176 °F) is valid when the
unit remains in its packaging. The RON 905
should not be stored at temperatures beyond
–30 to +50 °C (–22 to +122 °F): exceeding
this temperature range could result in
irreversible changes of up to 0.05 angular
seconds to the unit’s accuracy.
For this purpose, HEIDENHAIN offers the
DA 300 compressed air unit (filter
combination with pressure regulator and
fittings). The compressed air introduced
into the encoder must fulfill the requirements
of the following quality classes as per
ISO 8573-1:
Max. particle size and density of solid
contaminants:
Class 4 (max. particle size: 15 µm,
max. particle density: 8 mg/m3)
Total oil content:
Class 4 (oil content: 5 mg/m3)
Max. pressure dew point:
Class 4 (+29 °C at 10 · 105 Pa)
no classification
The following components are necessary
for connection to the RON, RPN, RCN and
ROD angle encoders:
M5 connecting piece for
RON/RPN/RCN/ROD
with gasket and throttle (dia. 0.3 mm)
for air-flow rate from 1 to 4 l/min
Id. Nr. 207835-04
M5 coupling joint, swiveling
with gasket
Id. Nr. 207834-02
For more information, ask for our DA 300
product information sheet.
DA 300
27
Protection against contact
After encoder installation, all rotating parts
(coupling on ROD, locking ring on RON,
RPN and RCN) must be protected against
accidental contact during operation.
Acceleration
Angle encoders are subject to various types
of acceleration during operation and
mounting.
The permissible angular acceleration
for all RON, RPN, RCN and ROD angle
encoders is over 105 rad/s2.
The indicated maximum values for
vibration are valid according to
IEC 60068-2-6.
The maximum permissible acceleration
values (semi-sinusoidal shock) for shock
and impact are valid for 6 ms
(IEC 60068-2-27).
Under no circumstances should a
hammer or similar implement be used to
adjust or position the encoder.
Natural frequency fN of coupling
The rotor and shaft coupling of ROD angle
encoders, as well as the stator and stator
coupling of RON, RPN and RCN angle
encoders, form a single vibrating springmass
system.
The natural frequency fN should be as
high as possible. With the RON, RPN and
RCN angle encoders, the natural frequency
fN is given in the respective specifications.
A prerequisite for the highest possible
natural frequency of ROD angle encoders
is the use of a shaft coupling with a high
torsional rigidity C.
fN= ·
fN: Natural frequency in Hz
C: Torsional rigidity of the coupling in Nm/rad
: Moment of inertia of the rotor in kgm2
If radial and/or axial acceleration occurs
during operation, the effect of the rigidity of
the encoder bearing, the encoder stator
and the coupling are also significant. If such
loads occur in your application, HEIDENHAIN
recommends consulting with the main
facility in Traunreut.
1
2 ·
C
I
Expendable parts
HEIDENHAIN encoders contain components
that are subject to wear, depending on the
application and manipulation. These include
in particular the following parts:
LED light source
Cables with frequent flexing
Additionally for encoders with integral
bearing:
Bearings
Shaft sealing rings for rotary and angular
encoders
Sealing lips for sealed linear encoders
System tests
Encoders from HEIDENHAIN are usually
integrated as components in larger systems.
Such applications require comprehensive
tests of the entire system regardless of
the specifications of the encoder.
The specifications given in the brochure
apply to the specific encoder, not to the
complete system. Any operation of the
encoder outside of the specified range or
for any other than the intended applications
is at the user’s own risk.
In safety-oriented systems, the higherlevel
system must verify the position
value of the encoder after switch-on.
DIADUR, AURODUR and MAGNODUR
are registered trademarks of
DR. JOHANNES HEIDENHAIN GmbH,
Traunreut.
Mounting
Work steps to be performed and dimensions
to be maintained during mounting
are specified solely in the mounting
instructions supplied with the unit. All data
in this catalog regarding mounting are
therefore provisional and not binding; they
do not become terms of a contract.
28
RON/RCN 200 Series
Integrated stator coupling
Hollow through shaft, diameter 20 mm
System accuracy ± 5" and ± 2.5"
= Bearing
= Required mating dimensions
Dimensions in mm
Accuracy ± 2.5" ± 5"
D1 20H6 20H7
D2 30H6 30H7
D3 20g6 20g7
T 0.01 0.02
29
Incremental Absolute
RON 225 RON 275 RON 275 RON 285 RON 287 RCN 226 RCN 226
Incremental signals TTL x 2 TTL x 5 TTL x 10 1 VPP 1 VPP
Line count
Integr. interpolation*
Output signals/rev
9000
2-fold/
18000
18000
5-fold/
90000
18000
10-fold/
180000
18000 16384
Reference mark* One RON 2xx:One
RON 2xxC:Distance-coded
–
Output frequency
Cutoff frequency –3dB
Max. 1 MHz
–
Max. 250 kHz
–
Max. 1 MHz
–
–
180 kHz 180 kHz
Absolute position values – EnDat
Positions per rev. – 67108864 (26 bits)
0.0000054° 0.02"
Elec. perm. speed – 1500 rpm
Recommended
measuring step
0.005° 0.001° 0.0005° 0.0001° 0.0001°
System accuracy ± 5" ± 2.5" ± 5" ± 2.5"
Power supply 5 V ± 10%/max. 150 mA (without load) 5 V ± 5%/max. 350 mA
(without load)
Electrical connection* Cable 1 m, radial, also usable axially;
with or without coupling
Cable 1 m, radial,
also usable axially;
with or without coupling
Max. cable length 50 m 150 m 150 m
Mech. permissible speed Max. 3000 rpm Max. 3000 rpm
Starting torque 0.08 Nm at 20 °C (68 °F) 0.08 Nm at 20 °C (68 °F)
Moment of inertia of rotor 73 · 10–6 kgm2 73 · 10–6 kgm2
Natural frequency 1200 Hz 1200 Hz
Permissible axis motion
of measured shaft
± 0.1 mm ± 0.1 mm
Vibration 55 to 2000 Hz
Shock6ms
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
70 °C (158 °F) 50 °C (122 °F) 70 °C (158 °F) 50 °C (122 °F)
Min. operating
temperature
Moving cable
Rigid cable
–10 °C (+14 °F)
–20 °C (–4 °F)
0 °C (32 °F)
0 °C (32 °F)
–10 °C (+14 °F)
–20 °C (–4 °F)
0 °C (32 °F)
0 °C (32 °F)
Protection IEC 60529 IP 64 IP 64
Weight Approx. 0.8 kg (1.8 lb) Approx. 0.8 kg (1.8 lb)
* Please indicate when ordering
Specifications
30
RON 785
Integrated stator coupling
Hollow through shaft, diameter 50 mm
System accuracy ± 2"
Dimensions in mm
= Bearing
= Required mating dimensions
31
Incremental
RON 785
Incremental signals 1 VPP
Line count 18000
Reference mark* RON 785:One
RON 785C:Distance-coded
Cutoff frequency –3dB 180 kHz
Recommended
measuring step
0.0001°
System accuracy ± 2"
Power supply 5 V ± 10%/max. 150 mA
Electrical connection* Cable 1 m, radial, also usable axially;
with or without coupling
Max. cable length 150 m
Mech. permissible speed Max. 1000 rpm
Starting torque 0.5 Nm at 20 °C (68 °F)
Moment of inertia of rotor 1.05 · 10–3kgm2
Natural frequency 1000 Hz
Permissible axis motion
of measured shaft
± 0.1 mm
Vibration 55 to 2000 Hz
Shock6ms
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
50 °C (122 °F)
Min. operating
temperature
0 °C (32 °F)
Protection IEC 60529 IP 64
Weight Approx. 2.5 kg (5.5 lb)
* Please indicate when ordering
= Bearing
= Required mating dimensions
RON/RCN 700 Series
Integrated stator coupling
Hollow through shaft, diameter 60 mm
System accuracy ± 2"
32
Dimensions in mm
33
Incremental Absolute
RON 786 RCN 727
Incremental signals 1 VPP 1 VPP
Line count* 18000
36000
32768
Reference mark* RON 786:One
RON 786C:Distance-coded
–
Cutoff frequency –3dB 180 kHz 180 kHz
Absolute position values – EnDat
Positions per rev. – 134217728 (27 bits)
0.0000027° 0.01"
Electrically permissible
speed for position value
– 300 rpm
Recommended
measuring step
0.0001° 0.0001°
System accuracy ± 2" ± 2"
Power supply 5 V ± 10%/max. 150 mA (without load) 5 V ± 5%/max. 350 mA
(without load)
Electrical connection* Cable 1 m, radial, also usable axially;
with or without coupling
Cable 1 m, radial, also usable axially;
with coupling
Max. cable length 150 m 150 m
Mech. permissible speed Max. 1000 rpm Max. 1000 rpm
Starting torque 0.5 Nm at 20 °C (68 °F) 0.5 Nm at 20 °C (68 °F)
Moment of inertia of rotor 1.2 · 10–3kgm2 1.2 · 10–3kgm2
Natural frequency 1000 Hz 1000 Hz
Permissible axis motion
of measured shaft
± 0.1 mm ± 0.1 mm
Vibration 55 to 2000 Hz
Shock6ms
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
50 °C (122 °F) 50 °C (122 °F)
Min. operating
temperature
0 °C (32 °F) 0 °C (32 °F)
Protection IEC 60529 IP 64 IP 64
Weight Approx. 2.5 kg (5.5 lb) Approx. 2.5 kg (5.5 lb)
* Please indicate when ordering
RON/RPN/RCN 800 Series
Integrated stator coupling
Hollow through shaft, diameter 60 mm
System accuracy ± 1"
Dimensions in mm
34
= Bearing
= Required mating dimensions
35
Incremental Absolute
RON 886 RPN 886 RCN 827
Incremental signals 1 VPP 1 VPP
Line count 36000 90000 (180000 signal periods) 32768
Reference mark* RON 886:One
RON 886C:Distance-coded
One –
Cutoff frequency –3dB
–6dB
180 kHz
–
800 kHz
1300 kHz
180 kHz
–
Absolute position values – EnDat
Positions per rev. – 134217728 (27 bits)
0.0000027° 0.01"
Electrically permissible
speed for position value
– 300 rpm
Recommended
measuring step
0.00005° 0.00001° 0.0001°
System accuracy ± 1" ± 1"
Power supply 5 V ± 10%/
max. 150 mA (without load)
5 V ± 10%/
max. 250 mA (without load)
5 V ± 5%/
max. 350 mA (without load)
Electrical connection* Cable 1 m, radial, also usable axially;
with or without coupling
Cable 1 m, radial,
also usable axially;
with or without coupling
Max. cable length 150 m 150 m
Mech. permissible speed Max. 1000 rpm Max. 1000 rpm
Starting torque 0.5 Nm at 20 °C (68 °F) 0.5 Nm at 20 °C (68 °F)
Moment of inertia of rotor 1.2 · 10–3 kgm2 1.2 · 10–3 kgm2
Natural frequency 1000 Hz 500 Hz 1000 Hz
Permissible axis motion
of measured shaft
± 0.1 mm ± 0.1 mm
Vibration 55 to 2000 Hz
Shock6ms
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
50 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
50 °C (122 °F) 50 °C (122 °F)
Min. operating
temperature
0 °C (32 °F) 0 °C (32 °F)
Protection IEC 60529 IP 64 IP 64
Weight Approx. 2.5 kg (5.5 lb) Approx. 2.5 kg (5.5 lb)
* Please indicate when ordering
36
RON 905
Integrated stator coupling
Blind hollow shaft
System accuracy ± 0.4"
= Bearing
= Required mating dimensions
Dimensions in mm
37
Incremental
RON 905
Incremental signals 11 µAPP
Line count 36000
Reference mark One
Cutoff frequency –3dB 40 kHz
Recommended
measuring step
0.00001°
System accuracy ± 0.4"
Power supply 5 V ± 5%/max. 250 mA
Electrical connection Cable 1 m, radial, with connector
Max. cable length 15 m
Mech. permissible speed Max. 100 rpm
Starting torque 0.05 Nm at 20 °C (68 °F)
Moment of inertia of rotor 0.345 · 10–3kgm2
Natural frequency 350 Hz
Permissible axis motion
of measured shaft
± 0.2 mm
Vibration 55 to 2000 Hz
Shock6ms
50 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
30 °C (86 °F)
Min. operating
temperature
10 °C (50 °F)
Protection IEC 60529 IP 64
Weight Approx. 4 kg (8.8 lb)
38
ROD 200 Series
For separate shaft coupling
System accuracy ± 5"
= Bearing
Dimensions in mm
39
Incremental
ROD 260 ROD 270 ROD 280
Incremental signals TTL TTL with 10-fold interpolation 1 VPP
Line count 18000
Reference mark* One ROD 280:One
ROD 280C:Distance-coded
Output frequency
Cutoff frequency –3dB
Max. 1 MHz
–
–
180 kHz
Recommended
measuring step
0.005° 0.0005° 0.0001°
System accuracy ± 5"
Power supply 5 V ± 10%/max. 150 mA (without load)
Electrical connection* Cable 1 m, radial, also usable axially;
with or without coupling
Max. cable length 100 m 150 m
Mech. permissible speed Max. 10000 rpm
Starting torque 0.01 Nm at 20 °C (68 °F)
Moment of inertia of rotor 20 · 10–6 kgm2
Shaft load Axial: 10 N
Radial: 10 N at shaft end
Vibration 55 to 2000 Hz
Shock6ms
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
70 °C (158 °F)
Min. operating
temperature
Moving cable
Rigid cable
–10 °C (+14 °F)
–20 °C (–4 °F)
Protection IEC 60529 IP 64
Weight Approx. 0.7 kg (1.5 lb)
* Please indicate when ordering
40
ROD 780/ROD 880
For separate shaft coupling
System accuracy ROD 780: ± 2"
ROD 880: ± 1"
= Bearing
Dimensions in mm
41
Incremental
ROD 780 ROD 880
Incremental signals 1 VPP
Line count* 18000
36000
36000
Reference mark* ROD x80:One
ROD x80C:Distance-coded
Cutoff frequency –3dB 180 kHz
Recommended
measuring step
0.0001° 0.00005°
System accuracy ± 2" ± 1"
Power supply 5 V ± 10%/max. 150 mA (without load)
Electrical connection* Cable 1 m, radial, also usable axially;
with or without coupling
Max. cable length 150 m
Mech. permissible speed Max. 1000 rpm
Starting torque 0.012 Nm at 20 °C (68 °F)
Moment of inertia of rotor 0.36 · 10–3kgm2
Shaft load Axial: 30 N
Radial: 30 N at shaft end
Vibration 55 to 2000 Hz
Shock6ms
100 m/s2 (IEC 60068-2-6)
300 m/s2 (IEC 60068-2-27)
Max. operating
temperature
50 °C (122 °F)
Min. operating
temperature
0 °C (32 °F)
Protection IEC 60529 IP 64
Weight Approx. 2.0 kg (4.4 lb)
* Please indicate when ordering
42
= Disk-to-scanning-reticle gap
= Required mating dimensions
= Space needed for service
= Seal
= Axis of bearing rotation
Scanning position A
ERP 880
Modular angle encoder
High accuracy due to interferential
scanning principle
Dimensions in mm
43
Incremental
ERP 880
Incremental signals 1 VPP
Line count 90000 (180000 signal periods)
Reference mark One
Cutoff frequency –3dB
–6dB
800 kHz
1.3 MHz
Recommended
measuring step
0.00001°
System accuracy1) ± 1"
Power supply 5 V ± 10%/max. 250 mA (without load)
Electrical connection With housing:Cable 1 m, radial, also usable
axially; with coupling
Without housing:Via 12-pin PCB connector (adapter cable Id. Nr.
372164-xx)
Max. cable length 150 m
Hub inside diameter 51.2 mm
Mech. permissible speed Max. 1000 rpm
Moment of inertia of rotor 1.2 · 10–3kgm2
Permissible axis motion
of measured shaft
± 0.05 mm
Vibration 55 to 2000 Hz
Shock6ms
50 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
50 °C (122 °F)
Min. operating
temperature
0 °C (32 °F)
Protection* IEC 60529 Without housing:IP 00 With housing:IP 40 With
housing and rotary shaft seal:
IP 64
Starting torque – 0.25 Nm
Weight 3.0 kg (6.6 lb) 3.1 kg (6.8 lb) incl. housing
* Please indicate when ordering
1) Without installation. Additional error caused by mounting inaccuracy
and inaccuracy from the bearing of the measured shaft are not included.
44
ERA 180
Modular angle encoder
Grating on steel drum
Incremental signals
Reference mark
Cutoff frequency –3dB
Power supply
Electrical connection
Max. cable length
Drum inside diameter*
Drum outside diameter*
Line count
System accuracy1)
Accuracy of the graduation2)
Recommended measuring step
Mech. permissible speed
Moment of inertia of rotor
Permissible axis motion
of measured shaft
Vibration 55 to 2000 Hz
Shock6ms
Max. operating temperature
Min. operating temperature
Protection* IEC 60529
Weight Scale drum
Protective cover
Scanning head
with cable
ERA 180
ERA 180 with protective cover
45
Incremental
ERA 180
1 VPP
One
500 kHz
5 V ± 10%/max. 150 mA (without load)
Cable 1 m (3.3 ft) with coupling
150 m
40 mm 80 mm 120 mm 180 mm 270 mm 425 mm 512 mm
80 mm 130 mm 180 mm 250 mm 330 mm 485 mm 562 mm
6000 9000 9000 18000 18000 36000 36000
± 7.5" ± 5" ± 5" ± 4" ± 4" ± 2.5" ± 2.5"
± 5" ± 3" ± 3" ± 3" ± 3" ± 2" ± 2"
0.0015° 0.001° 0.001° 0.0005° 0.0005° 0.0001° 0.0001°
40000 rpm 25000 rpm 18000 rpm 13000 rpm 10000 rpm 7000 rpm 6000 rpm
0.58 · 10–3kgm2 3.45 · 10–3kgm2 11.1 · 10–3kgm2 35.7 · 10–3kgm2 82.6 ·
10–3kgm2 281.8 · 10–3kgm2 399.7 · 10–3kgm2
± 0.5 mm (scale drum relative to scanning head)
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
80 °C (176 °F)
–10 °C (+14 °F)
Without protective cover:IP 00
With protective cover and compressed air:IP 40
IP 00
Approx. 0.5 kg
(1.1 lb)
Approx. 1.08 kg
(2.38 lb)
Approx. 1.17 kg
(2.58 lb)
Approx. 2.85 kg
(6.28 lb)
Approx. 3.3 kg
(7.3 lb)
Approx. 5 kg
(11 lb)
Approx. 5.3 kg
(12 lb)
Approx. 0.226 kg
(0.498 lb)
Approx. 0.365 kg
(0.805 lb)
Approx. 0.505 kg
(1.11 lb)
Approx. 0.675 kg
(1.49 lb)
–
Approx. 0.2 kg (0.44 lb)
* Please indicate when ordering
1) Without installation. Additional error caused by mounting inaccuracy
and inaccuracy from the bearing of the measured shaft are not included.
2) For other errors, see Measuring Accuracy
46
Dimensions in mm
ERA 180
= Bearing
= Mounting surfaces
= Mounting clearance set with spacer foil
= Mounting hole
= Back-off thread
Protective cover
47
Scale drum
inside diameter
D1 D2 D3 D4 D5 D6 D7 E
40 mm 40 –0.001
–0.005
50 64 80 80.4 100 110 – 60
80 mm 80 –0.001
–0.005
95 112 130 130.4 150 160 – 85
120 mm 120 –0.001
–0.008
140 162 180 180.4 200 210 144° 110
180 mm 180 –0.001
–0.008
200 232 250 250.4 270 280 150° 145
270 mm 270 –0.01 290 312 330 – – – – 185
425 mm 425 –0.01 445 467 485 – – – – 262.5
512 mm 512 –0.015 528 544 562 – – – – 301
Scale drum inside diameter
270mm
425mm
512mm
40mmto 180mm
48
ERM 280
Modular encoder
Magnetic scanning principle
= Bearing
= Mounting distance of 0.10 mm set with spacer foil
= Mounting distance of 0.15 mm set with spacer foil for version starting
in mid-2004
Dimensions in mm
D1 D2 D3 E
40 –0.007 50 75.44 43.4
70 –0.008 85 113.16 62.3
80 –0.008 95 128.75 70.1
120 –0.010 135 150.88 81.2
130 –0.012 145 176.03 93.7
180 –0.012 195 257.50 134.5
295 –0.016 310 326.90 169.2
New version:
Scheduled for mid-2004
49
Incremental
ERM 280
Incremental signals 1 VPP
Reference mark One
Cutoff frequency –3dB 200 kHz; as of mid-2004: 300 kHz
Power supply 5 V ± 10%/max. 150 mA (without load)
Electrical connection Cable 1 m (3.3 ft) with coupling
Max. cable length 150 m
Drum inside diameter* 40 mm 70 mm 80 mm 120 mm 130 mm 180 mm 295 mm
Drum outside diameter* 75.44 mm 113.16 mm 128.75 mm 150.88 mm 176.03 mm
257.50 mm 326.90 mm
Line count 600 900 1024 1200 1400 2048 2600
System accuracy1) ± 36" ± 25" ± 22" ± 20" ± 18" ± 12" ± 10"
Accuracy of the
graduation2)
± 14" ± 10" ± 9" ± 8" ± 7" ± 5" ± 4"
Recommended
measuring step
0.003° 0.002° 0.002° 0.002° 0.002° 0.001° 0.001°
Mech. perm. speed
as of mid-2004
24000 rpm/
40000 rpm
20000 rpm/
26000 rpm
18000 rpm/
22000 rpm
12000 rpm/
18000 rpm
10000 rpm/
15000 rpm
8000 rpm/
10000 rpm
5000 rpm/
7000 rpm
Moment of inertia of rotor 0.34 · 10–3
kgm2
1.6 · 10–3
kgm2
2.7 · 10–3
kgm2
3.5 · 10–3
kgm2
7.7 · 10–3
kgm2
38 · 10–3
kgm2
44 · 10–3
kgm2
Perm. axial movement ± 1 mm; as of mid-2004: ± 1.25 mm
Vibration 55 to 2000 Hz
Shock6ms
100 m/s2 (IEC 60068-2-6); as of mid-2004: 400 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
100 °C (212 °F)
Min. operating
temperature
–10 °C (+14 °F)
Protection IEC 60529 IP 66; as of mid-2004: IP 67
Weight
Scale drum Approx.
0.35 kg
(0.77 lb)
Approx.
0.69 kg
(1.52 lb)
Approx.
0.89 kg
(1.96 lb)
Approx.
0.72 kg
(1.59 lb)
Approx.
1.2 kg
(2.65 lb)
Approx.
3.0 kg
(6.6 lb)
Approx.
1.7 kg
(3.75 lb)
Scanning head
with cable
Approx. 0.15 kg (0.33 lb)
* Please indicate when ordering; other versions available upon request
Cursive: version available as of mid-2004
1) Without installation. Additional error caused by mounting inaccuracy
and inaccuracy from the bearing of the measured shaft are not included.
2) For other errors, see Measuring Accuracy
50
ERO 785
Modular angle encoder
Circular scale with hub
Hub inside
diameter
Line count E B C
155.1 36000 132 0.05 ±0.02 0.02
102.2 94.5 0.20 ±0.02
47.2 67.35 0.08 ±0.01 0.01
Dimensions in mm
1) Mean graduation diameter
= Bearing
= Cutout for mounting
= Position of the reference mark to an integral mounting thread ±2°
= Graduation
= Graduation surface
= Mounting surface
= Flange socket
Hub inside diameter
155.1mm
102.2mm
47.2mm
51
Incremental
ERO 785
Incremental signals 1 VPP
Line count 36000
Reference mark One
Cutoff frequency –3dB 180 kHz
Recommended
measuring step
0.0001°
System accuracy1) ± 4.2" ± 3" ± 2.2"
Accuracy of the
graduation2)
± 3.7" ± 2.5" ± 1.7"
Power supply 5 V ± 10%/max. 150 mA
Electrical connection Cable 0.3 m (1 ft) with flange socket (male) on
mounting base
Max. cable length Max. 150 m
Hub inside diameter* 47.2 mm 102.2 mm 155.1 mm
Mech. permissible speed Max. 8000 rpm Max. 6000 rpm Max. 4000 rpm
Moment of inertia of rotor 620 · 10–6 kgm2 3700 · 10–6 kgm2 26000 · 10–6
kgm2
Perm. axial movement See the tolerance of scanning gap “B” in the
dimension drawing
Vibration 55 to 2000 Hz
Shock6ms
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
50 °C (122 °F)
Min. operating
temperature
0 °C (32 °F)
Protection IEC 60529 IP 00
Weight
Scanning unit Approx. 0.185 kg (0.4 lb)
Circular scale with hub 0.46 kg (1.0 lb) 0.87 kg (1.9 lb) 2.6 kg (5.7
lb)
* Please indicate when ordering
1) Without installation. Additional error caused by mounting inaccuracy
and inaccuracy from the bearing of the measured shaft are not included.
2) For other errors, see Measuring Accuracy
52
ERA 700 Series
Modular angle encoder for inside diameters
Full-circle and segment versions
Dimensions in mm
ERA 781C Scale tape
* = Max. change during operation
= Bearing
= Required mating dimensions for the scale tape (not to scale)
L = Distance of the mounting holes
L1 = Traverse path
L2 = Measuring range in radian measure
= Measuring range in degrees (segment angle)
= Scanning gap (distance between scanning reticle and scale-tape
surface)
= Mounting clearance for mounting bracket. Spacer foil 0.5 mm
= Scale-tape thickness
= Distance between floor of scale-tape slot and threaded mounting hole
= Distance between mounting surface and scale-tape slot
= View of customer boring
= Cam disk for tensioning the scale tape
= Position of first reference mark
= Notch for removing scale tape (1 x b = 2 mm)
53
Incremental
ERA 780C Full-circle version
ERA 781C Segment version, scale-tape mounting with tensioning elements
Incremental signals 1 VPP
Reference mark Distance-coded, nominal increment of 1000 grating periods
Cutoff frequency –3dB 180 kHz
Power supply 5 V ± 10%/max. 150 mA (without load)
Electrical connection Cable 3 m (9.9 ft) with coupling
Max. cable length 150 m
Scale-slot diameter* 318.58 mm 458.62 mm 573.20 mm 1146.1 mm
Line count
ERA 780C full circle – 36000 45000 90000
ERA 781C segment* 72°: 50003)
144°:100003)
50°: 5000
100°:10000
200°:20000
160°:20000 –
Recommended measuring
step
0.0002° 0.0001° 0.00005° 0.00002°
System accuracy1)
ERA 780C full circle – ± 3.5" ± 3.4" ± 3.2"
ERA 781C segment See Measuring Accuracy
Accuracy of the
graduation2)
± 3"
Mech. permissible speed Max. 500 rpm
Perm. axial movement ± 0.2 mm
Vibration 55 to 2000 Hz
Shock6ms
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
50 °C (122 °F) (thermal coefficient of expansion of the scale substrate
between 9 · 10–6K–1 and 12 · 10–6K–1)
Min. operating
temperature
–10 °C (+14 °F)
Protection IEC 60529 IP 00
Weight
Scanning unit Approx. 0.35 kg (0.77 lb)
Scale tape 30 g/m (7.1 oz/m)
* Please indicate when ordering; other versions available upon request
1) Without installation. Additional error caused by mounting inaccuracy
and inaccuracy from the bearing of the measured shaft are not included.
2) For other errors, see Measuring Accuracy
3) Corresponds to 25000 lines on a full circle
54
ERA 800 Series
Modular angle encoder for outside diameters
Full-circle and segment versions
ERA 880C Full-circle version
ERA 881C Circle-segment version,
scale tape secured with tensioning elements
ERA 882C Circle-segment version,
scale tape without tensioning elements
55
Incremental
ERA 880C Full-circle version
ERA 881C Segment version, scale-tape mounting via tensioning elements
ERA 882C Segment version, scale tape without tensioning elements
Incremental signals 1 VPP
Reference mark Distance-coded, nominal increment of 1000 grating periods
Cutoff frequency –3dB 180 kHz
Power supply 5 V ± 10%/max. 150 mA (without load)
Electrical connection Cable 3 m (9.9 ft) with coupling
Max. cable length 150 m
Scale-slot diameter* 317.99 mm 458.04 mm 572.63 mm
Line count
ERA 880C full circle – 36000 45000
ERA 881C/
ERA 882C segment*
72°: 50003)
144°:100003)
50°: 5000
100°:10000
200°:20000
160°:20000
Recommended
measuring step
0.0002° 0.0001° 0.00005°
System accuracy1)
ERA 880C full circle – ± 3.5" ± 3.4"
ERA 881C/
ERA 882C segment
See Measuring Accuracy
Accuracy of the
graduation2)
± 3"
Mech. permissible speed Max. 100 rpm
Perm. axial movement ± 0.2 mm
Vibration 55 to 2000 Hz
Shock6ms
100 m/s2 (IEC 60068-2-6)
1000 m/s2 (IEC 60068-2-27)
Max. operating
temperature
50 °C (122 °F) (thermal coefficient of expansion of the scale substrate
between 9 · 10–6K–1 and 12 · 10–6K–1)
Min. operating
temperature
–10 °C (+14 °F)
Protection IEC 60529 IP 00
Weight
Scanning unit Approx. 0.35 kg (0.77 lb)
Scale tape 30 g/m (7.1 oz/m)
* Please indicate when ordering; other versions available upon request
1) Without installation. Additional error caused by mounting inaccuracy
and inaccuracy from the bearing of the measured shaft are not included.
2) For other errors, see Measuring Accuracy
3) Corresponds to 25000 lines on a full circle
56
ERA 800 Series
Dimensions in mm
* = Max. change during operation
= Bearing
= Required mating dimensions for scale-tape slot (not to scale)
= Scanning gap (distance between scanning reticle and scale-tape
surface)
= Mounting clearance for mounting bracket. Spacer foil 0.5 mm
= Scale-tape thickness
= Distance between floor of scale-tape slot and threaded mounting hole
= Distance between mounting surface and scale-tape slot
ERA 880C Scale tape
57
ERA 882C Scale tape
ERA 881C Scale tape
* = Max. change during operation
= Bearing
= View of customer boring
= Position of first reference mark
L = With ERA 881C:Positions of the tensioning elements
= With ERA 882C:Distance of mounting holes
L1 = Traverse path
L2 = Measuring range in radian measure
= Measuring range in degrees (segment angle)
58
Interfaces
Incremental Signals 1 VPP
HEIDENHAIN encoders with 1 VPP
interface provide voltage signals that can
be highly interpolated.
The sinusoidal incremental signals A and B
are phase-shifted by 90° elec. and have an
amplitude of typically 1 VPP. The illustrated
sequence of output signals—with B lagging
A—applies for the direction of motion
shown in the dimension drawing.
The reference mark signal R has a usable
component Gof approx. 0.5 V. Next to the
reference mark, the output signal can be
reduced by up to 1.7 V to an idle level H.
This must not cause the subsequent
electronics to overdrive. In the lowered
signal level, signal peaks can also appear
with the amplitude G.
The data on signal amplitude apply when
the power supply given in the specifications
is connected to the encoder. They refer to
a differential measurement at the 120 ohm
terminating resistor between the associated
outputs. The signal amplitude decreases
with increasing frequency. The cutoff
frequency indicates the scanning frequency
at which a certain percentage of the original
signal amplitude is maintained:
–3 dB cutoff frequency:
70%of the signal amplitude
–6 dB cutoff frequency:
50%of the signal amplitude
Interpolation/resolution/measuring step
The output signals of the 1 VPP interface
are usually interpolated in the subsequent
electronics in order to attain sufficiently
high resolutions. For velocity control,
interpolation factors are commonly over
1000 in order to receive usable velocity
information even at low speeds.
Measuring steps for position measurement
are recommended in the specifications. For
special applications, other resolutions are
also possible.
Signal period
360° elec.
(Rated value)
A, B, R measured with an oscilloscope in differential mode
Signal amplitude [%]
–3dB cutoff frequency
–6dB cutoff frequency Scanning frequency [kHz]
Cutoff frequency
Typical signal
amplitude curve
with respect to the
scanning frequency
Interface Sinusoidal voltage signals 1 VPP
Incremental signals Two nearly sinusoidal signals A and B
Signal amplitude M: 0.6 to 1.2 VPP; 1 VPP typical
AsymmetryIP – NI/2M: 0.065
Amplitude ratio MA/MB: 0.8 to 1.25
Phase angle I 1 + 2I/2: 90° ± 10° elec.
Reference mark
signal
One or more signal peaks R
Usable component G: 0.2 to 0.85 V
Quiescent value H: 0.04 V to 1.7 V
Switching threshold E, F: 40 mV
Zero crossovers K, L: 180° ± 90° elec.
Connecting cable
Cable length
Propagation time
HEIDENHAIN cable with shielding
PUR [4(2 · 0.14 mm2) + (4 · 0.5mm2)]
Max. 150 m distributed capacitance 90 pF/m
6 ns/m
Any limited tolerances in the encoders are listed in the specifications.
59
12-pin
HEIDENHAIN
coupling
12-pin
HEIDENHAIN
connector
15-pin D-sub connector,
female,
for HEIDENHAIN controls
and IK 220
12-pin
PCB connector
on ERP 880
Power supply Incremental signals Other signals
12 2 10 11 5 6 8 1 3 4 7 9
1 9 2 11 3 4 6 7 10 12 14 5/8/13/15
2a 2b 1a 1b 6b 6a 5b 5a 4b 4a 3a 3b
UP Sensor
UP
0 V Sensor
0 V
A+ A– B+ B– R+ R– Vacant Vacant
Brown/
Green
Blue White/
Green
White Brown Green Gray Pink Red Black Violet –
Shield is on housing; UP = Power supply
Sensor: The sensor line is connected internally to the respective the
power supply.
Vacant pins or wires must not be used!
Electrical Connections
Input circuitry of the subsequent
electronics
Dimensioning
Operational amplifier MC 34074
Z0 = 120
R1 = 10 k and C1 = 100 pF
R2 = 34.8 k and C2 = 10 pF
UB = ±15 V
U1 approx. U0
–3dB cutoff frequency of circuitry
Approx. 450 kHz
Approx. 50 kHz with C1 = 1000 pF
and C2= 82pF
This circuit variant does reduce the
bandwidth of the circuit, but in doing so it
improves its noise immunity.
Circuit output signals
Ua = 3.48 VPP typical
Gain 3.48
Signal monitoring
A threshold sensitivity of 250 mVPP is to be
provided for monitoring the 1 VPP incremental
signals.
Incremental
signals
Reference mark
signal
Ra < 100 ,
approx. 24
Ca < 50 pF
Ia<1mA
U0 = 2.5 V ±0.5 V
(with respect to 0 V of
the power supply)
1 VPP
Subsequent electronics Encoder
Pin Layout
60
Line count/
Interpolation
Measuring
step1)
Scanning
frequency
Elec. perm.
speed
Min. edge
separation2) a
RON 225 9000/2-fold 0.005° 500 kHz 3000 rpm
(due to
mechanics)
0.125 µs
ROD 260 18000/none 0.005° 1 MHz
RON 275 18000/5-fold 0.001° 50 kHz 166 rpm 0.98 µs
RON 275
ROD 270
18000/10-fold 0.0005° 100 kHz 333 rpm 0.23 µs
1) After 4-fold evaluation 2) Taking digitizing effects into account
Interfaces
Incremental Signals TTL
HEIDENHAIN encoders with TTL
interface incorporate electronics that
digitize sinusoidal scanning signals with or
without interpolation.
The incremental signals are transmitted
as the square-wave pulse trains Ua1 and Ua2,
phase-shifted by 90° elec. The reference
mark signal consists of one or more
reference pulses Ua0, which are gated with
the incremental signals. In addition, the
integrated electronics produce their inverse
signals , and for noise-proof
transmission. The illustrated sequence of
output signals—with Ua2 lagging Ua1—
applies for the direction of motion shown
in the dimension drawing.
The fault-detection signal indicates
fault conditions such as breakage of the
power line or failure of the light source. It
can be used for such purposes as machine
shut-off during automated production.
The distance between two successive
edges of the incremental signals Ua1 and
Ua2 through 1-fold, 2-fold or 4-fold
evaluation is one measuring step.
The subsequent electronics must be
designed to detect each edge of the squarewave
pulse. The minimum edge separation
alisted in the Specificationsapplies for
the illustrated input circuitry with a cable
length of 1m, and refers to a measurement
at the output of the differential line receiver.
Propagation-time differences in cables
additionally reduce the edge separation by
0.2 ns per meter of cable length. To prevent
counting error, design the subsequent
electronics to process as little as 90% of
the resulting edge separation. The max.
permissible shaft speed or traversing
velocity must never be exceeded.
Interface Square-wave signals TTL
Incremental signals 2 TTL square-wave signals Ua1, Ua2 and their
inverted signals
,
Reference mark
signal
Pulse width
Delay time
One or more TTL square-wave pulses Ua0 and their inverse
pulses
90° elec. (other widths available on request); LS 323:nongated
|td| 50 ns
Fault detection
signal
Pulse width
One TTL square-wave pulse
Improper function: LOW (on request: Ua1/Ua2 high impedance)
Proper function: HIGH
tS 20 ms
Signal level Differential line driver as per EIA standard RS 422
UH 2.5 V at –IH = 20mA
UL 0.5 V at IL = 20mA
Permissible load Z0 100 between associated outputs
|ILI 20 mA max. load per output
Cload 1000 pF with respect to 0 V
Outputs protected against short circuit to 0 V
Switching times
(10% to 90%)
t+ / t– 30 ns (typically 10 ns)
with 1 m cable and recommended input circuitry
Connecting cable
Cable length
Propagation time
HEIDENHAIN cable with shielding
PUR [4(2 × 0.14 mm2) + (4 × 0.5mm2)]
Max. 100m( max. 50 m) with distributed capacitance 90 pF/m
6 ns/m
!
Signal period 360° elec. Fault
Measuring step after
4-fold evaluation
Inverse signals , , are not shown
61
12-pin
HEIDENHAIN
coupling
12-pin
HEIDENHAIN
connector
Power supply Incremental signals Other signals
12 2 10 11 5 6 8 1 3 4 7 9 /
UP Sensor
UP
0 V Sensor
0 V
Ua1 Ua2 Ua0 Vacant Vacant
Brown/
Green
Blue White/
Green
White Brown Green Gray Pink Red Black Violet / Yellow
Shield is on housing; UP = Power supply
Sensor: The sensor line is connected internally to the respective the
power supply.
Vacant pins or wires must not be used!
The permissible cable length for transmission
of the TTL square-wave signals to
the subsequent electronics depends on the
edge separation a.It is max. 100 m, or 50m
for the fault detection signal. This requires,
however, that the power supply (see
Specifications) be ensured at the encoder.
The sensor lines can be used to measure
the voltage at the encoder and, if required,
correct it with an automatic system (remote
sense power supply).
Cable lengths [m]
without
with
Permissible
cable length
with respect to the
edge separation
Incremental signals
Reference mark
signal
Fault detection
signal
Subsequent electronics Encoder Input circuitry of the subsequent
electronics
Dimensioning
IC1 = Recommended differential line
receivers
DS 26 C 32 AT
Only for a> 0.1 µs:
AM 26 LS 32
MC 3486
SN 75 ALS 193
R1 = 4.7 k
R2 = 1.8 k
Z0 = 120
C1 = 220 pF (serves to improve noise
immunity)
Pin Layout
Edge separation [µs]
62
Input circuitry of subsequent electronics
Data transfer
IC1 = RS 485
differential line receiver
and driver
C3 = 330 pF
Z0 = 120
Incremental signals
As a bidirectional interface, the EnDat
(Encoder Data) interface for absolute
encoders is capable of producing absolute
position values as well as requesting or
updating information stored in the encoder.
Thanks to the serial transmission method
only four signal lines are required. The
type of transmission (position values or
parameters) is selected by mode commands
that the subsequent electronics send to the
encoder. The data are transmitted in
synchronism with the clock signal from
the subsequent electronics.
Benefits of the EnDat interface
One interface for all absolute encoders,
whereby the subsequent electronics can
automatically distinguish between EnDat
and SSI.
Complementary output of incremental
signals (optional for highly dynamic
control loops).
Automatic self-configuration during
encoder installation, since all information
required by the subsequent electronics is
already stored in the encoder.
Reduced wiring cost
For standard applications, six lines are
sufficient.
High system security through alarms
and messages that can be evaluated in the
subsequent electronics for monitoring
and diagnosis. No additional lines are
required.
Minimized transmission times through
adaptation of the data word length to the
resolution of the encoder and through
high clock frequencies.
High transmission reliability through
cyclic redundancy checks.
Datum shifting through an offset value
in the encoder.
It is possible to form a redundant
system, since the absolute value and
incremental signals are output
independently from each other.
Interfaces
Absolute Position Values
Cable length [m]
Clock frequency [kHz]
Interface EnDat 2.1 serial bidirectional
Data transfer Absolute position values and parameters
Data input Differential line receiver according to EIA standard RS 485
for
CLOCK, CLOCK, DATA and DATA signals
Data output Differential line driver according to EIA standard RS 485
for the
DATA and DATA signals
Signal level Differential voltage output > 1.7 V with Z0 = 120 load*)
(EIA standard RS 485)
Code Pure binary code
Ascending
position values
In traverse direction indicated by arrow (see Dimensions)
Incremental Signals 1 VPP (see Incremental Signals 1 VPP)
Connecting cable
Cable length
Propagation time
HEIDENHAIN cable with shielding
PUR [(4 x 0.14 mm2) +4(2 x 0.14 mm2) + (4 x 0.5mm2)]
Max. 150 m with 90 pF/m distributed capacitance
6 ns/m
*) Terminating and receiver input resistor
Permissible
clock frequency
with respect to
cable lengths
Encoder Subsequent electronics
63
Function of the EnDat Interface
The EnDat interface outputs absolute
position values, optionally makes incremental
signals available, and permits
reading from and writing to the memory
in the encoder.
Selecting the transmission type
Position values and memory contents are
transmitted serially through the DATA lines.
The type of information to be transmitted is
selected by mode commands. Mode
commands define the content of the information
that follows. Every mode command
consists of 3 bits. To ensure transmission
reliability, each bit is also transmitted
inverted. If the encoder detects an erroneous
mode transmission, it transmits an error
message.
The following mode commands are
available:
Encoder transmit absolute position value
Selection of the memory area
Encoder transmit/receive parameters of
the last defined memory area
Encoder transmit test values
Encoder receive test commands
Encoder receive RESET
Parameters
The encoder provides several memory
areas for parameters. These can be read
from by the subsequent electronics, and
some can be written to by the encoder
manufacturer, the OEM, or even the end
user. Certain memory areas can be
write-protected.
The parameters, which in most cases
are set by the OEM, largely define
the function of the encoder and the
EnDat interface. When the encoder is
exchanged, it is therefore essential that its
parameter settings are correct. Attempts to
configure machines without including OEM
data can result in malfunctions. If there is
any doubt as to the correct parameter
settings, the OEM should be consulted.
Memory Areas
Parameters of the encoder manufacturer
This write-protected memory area contains
all information specific to the encoder,
such as encoder type (linear/angular,
singleturn/multiturn, etc.), signal periods,
number of position values per revolution,
transmission format of absolute position
values, direction of rotation, maximum
permissible speed, accuracy dependent
on shaft speeds, support from warnings
and alarms, part number, and serial
number. This information forms the basis
for automatic configuration.
Parameters of the OEM
In this freely definable memory area, the
OEM can store his information. For
example, the “electronic ID label” of the
motor in which the encoder is integrated,
indicating the motor model, maximum
current rating, etc.
Operating parameters
This area is available to the customer for a
datum shift. It can be protected against
overwriting.
Operating status
This memory area provides detailed alarms
or warnings for diagnostic purposes. Here it
is also possible to activate write protection
for the OEM-parameter and operating
parameter memory areas, and interrogate
its status.
Once activated, the write protection cannot
be reversed.
Monitoring and Diagnostic Functions
Alarms and warnings
The EnDat interface enables comprehensive
monitoring of the encoder without requiring
an additional transmission line. An alarm
becomes active if there is a malfunction in
the encoder that is presumably causing
incorrect position values. At the same time,
an alarm bit is set in the data word. Alarm
conditions include:
Light unit failure
Signal amplitude too low
Error in calculation of position value
Power supply too high/low
Current consumption is excessive
Warnings indicate that certain tolerance
limits of the encoder have been reached or
exceeded—such as shaft speed or the limit
of light source intensity compensation
through voltage regulation—without implying
that the measured position values are
incorrect. This function makes it possible
to issue preventive warnings in order to
minimize idle time. The alarms and warnings
supported by the respective encoder are
saved in the “parameters of the encoder
manufacturer” memory area.
Reliable data transfer
To increase the reliability of data transfer, a
cyclic redundancy check (CRC) is performed
through the logical processing of the
individual bit values of a data word. This
5-bit long CRC concludes every transmission.
The CRC is decoded in the receiver
electronics and compared with the data
word. This largely eliminates errors caused
by disturbances during data transfer.
Block diagram: Absolute encoder with EnDat interface
Incremental
signals
Absolute
position value
Operating
status
Operating
parameters
(e.g., datum
shift)
Parameters of
the encoder
manufacturer
Parameters
of the OEM
1 VPP A
1 VPP B
UP Power
0 V supply
EnDat interface
Absolute encoder Subsequent
electronics
64
Encoder saves
position value
Position value Cyclic redundancy
check
Subsequent electronics
transmit mode command
Mode command
Interrupted clock
The interrupted clock is intended particularly
for time-clocked systems such as closed
control loops. At the end of the data word
the clock signal is set to HIGH level. After
10 to 30 µs ( tm), the data line falls back to
LOW. Then a new data transmission can
begin by starting the clock.
Continuous clock
For applications that require fast acquisition
of the measured value, the EnDat interface
can have the clock run continuously.
Immediately after the last CRC bit has been
sent, the DATA line is switched to HIGH for
one clock cycle, and then to LOW. The
new position value is saved with the very
next falling edge of the clock and is output
in synchronism with the clock signal
immediately after the start bit and alarm bit.
Because the mode command encoder
transmits position valueis needed only
before the first data transmission, the
continuous-clock transfer mode reduces
the length of the clock-pulse group by 10
periods per position value.
Data transfer
The two types of EnDat data transfer are
position value transfer and parameter
transfer.
Control Cycles for Transfer of Position
Values
The clock signal is transmitted by the
subsequent electronics to synchronize the
data output from the encoder. When not
transmitting, the clock signal defaults to
HIGH. The transmission cycle begins with
the first falling edge. The measured values
are saved and the position value calculated.
After two clock pulses (2T), the subsequent
electronics send the mode command
Encoder transmit position value.
After successful calculation of the absolute
position value (tcal—see table), the start bit
begins the data transmission from the
encoder to the subsequent electronics.
The subsequent alarm bit is a common
signal for all monitored functions and serves
for failure monitoring. It becomes active if a
malfunction of the encoder might result in
incorrect position values. The exact cause
of the trouble is saved in the encoder’s
“operating status” memory where it can
be interrogated in detail.
The absolute position value is then
transmitted, beginning with the LSB. Its
length depends on the encoder being used.
It is saved in the encoder manufacturer’s
memory area. Since EnDat does not need
to fill superfluous bits with zeros as in SSI,
the transmission time of the position value
to the subsequent electronics is minimized.
Data transmission is concluded with the
cyclic redundancy check (CRC).
ROC, ECN,
ROQ, EQN1)
ECI/EQI1) RCN1) LC1)
Clock frequency fC 100 kHz to 2 MHz
Calculation time for
Position value
Parameter
tcal
tac
250 ns
Max. 12 ms
5 µs
Max. 12 ms
10 µs
Max. 12 ms
1ms
Max. 12 ms
Recovery time tm 10 to 30 µs
HIGH Pulse width tHI 0.2 to 10 µs
LOW pulse width tLO 0.2 µs to 50 ms 0.2 to 30 µs
1)See also Rotary Encoders, Position Encoders for Servo Drives,
1) Sealed Linear Encoderscatalogs
Save new
position value
Position value
Save new
position value
CRC CRC
n = 0 to 5; depending on the system
65
Encoder Subsequent electronics
Latch signal
Counter
Subdivision
Parallel
interface
Comparator
Control cycles for transfer of parameters
(mode command 001110)
Before parameter transfer, the memory
area is specified with the mode command
Select memory areaand a subsequent
memory-range-select code (MRS). The
possible memory areas are stored in the
parameters of the encoder manufacturer.
Due to internal access times to the
individual memory areas, the time tac may
reach 12 ms.
Reading parameters from the encoder
(mode command 100011)
After selecting the memory area, the
subsequent electronics transmit a complete
communications protocol beginning with
the mode command Encoder transmit
parameters,followed by an 8-bit address
and 16 bits with random content. The
encoder answers with the repetition of the
address and 16 bits with the contents of
the parameter. The transmission cycle is
concluded with a CRC check.
Writing parameters to the encoder
(mode command 011100)
After selecting the memory area, the
subsequent electronics transmit a complete
communications protocol beginning with
the mode command Encoder receive
parameters,followed by an 8-bit address
and a 16-bit parameter value. The encoder
answers by repeating the address and the
contents of the parameter. The CRC check
concludes the cycle.
Transmitter in encoder inactive
Receiver in encoder active
Transmitter in encoder active
MRS code
Address
Address
x = random y = parameter Acknowledgment
MRS code
Address
Address
Parameter
8 Bit 16 Bit 8 Bit 16 Bit
Synchronization of the serially
transmitted code value with the
incremental signal
Absolute encoders with EnDat interface
can exactly synchronize serially transmitted
absolute position values with incremental
values. With the first falling edge (latch signal)
of the CLOCK signal from the subsequent
electronics, the scanning signals of the
individual tracks in the encoder and counter
are frozen, as are also the A/D converters
for subdividing the sinusoidal incremental
signals in the subsequent electronics.
The code value transmitted over the serial
interface unambiguously identifies one
incremental signal period. The position value
is absolute within one sinusoidal period of
the incremental signal. The subdivided
incremental signal can therefore be
appended in the subsequent electronics to
the serially transmitted code value.
After power on and initial transmission of
position values, two redundant position
values are available in the subsequent electronics.
Since encoders with EnDat interface
guarantee a precise synchronization—
regardless of cable length—of the serially
transmitted absolute value with the
incremental signals, the two values can be
compared in the subsequent electronics.
This monitoring is possible even at high
shaft speeds thanks to the EnDat interface’s
short transmission times of less than 50 µs.
This capability is a prerequisite for modern
machine design and safety concepts.
1 VPP
1 VPP
66
Pin Layout
15-pin D-sub connector,
male
for IK 115
15-pin D-sub connector,
female,
for HEIDENHAIN controls and
IK 220
Power supply Incremental Signals Absolute position values
4 12 2 10 6 1 9 3 11 5 13 8 15
1 9 2 11 13 3 4 6 7 5 8 14 15
UP Sensor
UP
0 V Sensor
0 V
Inside
shield
A+ A– B+ B– DATA DATA CLOCK CLOCK
Brown/
Green
Blue White/
Green
White / Green/
Black
Yellow/
Black
Blue/
Black
Red/
Black
Gray Pink Violet Yellow
Shield is on housing; UP = power supply
Sensor: The sensor line is connected internally to the respective power
supply.
Vacant pins or wires must not be used!
17-pin
HEIDENHAIN
coupling or
flange socket
12-pin PCB connector
Power supply Incremental Signals Absolute position values
7 1 10 4 11 15 16 12 13 14 17 8 9
1b 6a 4b 3a / 2a 5b 4a 3b 6b 1a 2b 5a
UP Sensor
UP
0 V Sensor
0 V
Inside
shield
A+ A– B+ B– DATA DATA CLOCK CLOCK
Brown/
Green
Blue White/
Green
White / Green/
Black
Yellow/
Black
Blue/
Black
Red/
Black
Gray Pink Violet Yellow
Shield is on housing; UP = power supply; T = temperature
Sensor: The sensor line is connected internally to the respective the
power supply.
Vacant pins or wires must not be used!
67
Flange socket: A flange socket is
permanently mounted on the encoder or
machine housing, has an external thread,
and is available with male or female
contacts.
D-sub connector: D-sub connectors fit on
HEIDENHAIN controls and IK counter
cards.
Coupling: A connecting element with
external thread, regardless of whether the
contacts are male or female.
Connector: A connecting element with
coupling ring, regardless of whether the
contacts are male or female.
Contacts:
Male contacts
Female contacts
Pin numbering
The pins on connectors are numbered in
directions opposite to those on couplings,
regardless of whether the contacts are
male or female. Since couplings and flange
sockets both have external threads, they
have the same pin-numbering direction.
Connecting Elements and Cables
General Information
Protection: When engaged, the connections
(except D-sub connectors) provide protection
to IP 67 (IEC 60529 / IEC 144). When not
engaged, there is no protection (IP 00).
Connector insulated Coupling insulated
Flange socket D-sub connector
x
x: 42.7
y: 41.7
y
Coupling on mounting base insulated
68
Connecting Elements and Cables
1 VPP and TTL
Coupling on encoder cable Coupling (male), 12-pin
For encoder cable 6 mm 291698-03
Coupling mounted on encoder cable Mounted coupling
(male), 12-pin
For encoder cable 6 mm 291698-08
Polyurethane (PUR) connecting cable dia. 8 mm
[4(2 x 0.14 mm2) + (4 x 0.5mm2)]
for encoders with coupling
Mating element on connecting cable
to coupling on encoder cable or
flange socket
Connector (female),
12-pin
Complete with connector (female)
and connector (male)
298399-xx
For connecting cable 8 mm 291697-05
Complete with connector (female)
and D-sub connector (female)
15-pin for HEIDENHAIN controls
and IK 220
310199-xx Connector on cable for connection
to subsequent electronics
Connector (male), 12-pin
For connecting cable 8 mm 291697-08
With one connector (female) 309777-xx Flange socket for connecting cable
to
subsequent electronics
Flange socket (female),
12-pin: 315892-08
Coupling on mounting
base (female),
for cable dia. 8 mm,
12-pin: 291698-07
Without connectors 244957-01
Adapter cable for ERP 880 dia. 4.5mm
With one connector
with 12-pin PCB connector
with shield connection clamp
372164-xx
Adapter connector 1 VPP/ 11 µAPP
For converting the 1-VPP output signals
to 11-µAPP input signals for the
subsequent electronics; equipped
with connector (female) 12-pin and
connector (male) 9-pin
364914-01
69
Connecting element on encoder
cable
Coupling (male),
17-pin
For encoder cable dia. 4.5 mm
dia. 6 mm
291698-25
291698-26
Polyurethane (PUR) dia. 8 mm
[(4 x 0.14 mm2) + 4(2 x 0.14 mm2) + (4 x 0.5mm2)]
Mating element on connecting cable
for connecting element on encoder
Connector (female),
17-pin
Complete with connector (female) and
D-sub connector (male) for IK 115
324544-xx
For connecting cable 8 mm 291697-26
Complete with connector (female)
and D-sub connector (female) for
HEIDENHAIN controls and IK 220.
332115-xx Connector on cable for connection to
subsequent electronics
Connector (male), 17-pin
For connecting cable 8 mm 291697-27
With one connector (female) 309778-xx Coupling on extension cable
Coupling (male),
17-pin
For connecting cable 8 mm 291698-27
Without connectors 266306-01
EnDat Interface
70
General Electrical Information
Cable
Lengths
The cable lengths listed in the Specifications
apply only for HEIDENHAIN cables and the
recommended input circuitry of subsequent
electronics.
Durability
All encoders use polyurethane (PUR) cables.
PUR cables are resistant to oil, hydrolysis and
microbes in accordance with VDE 0472. They
are free of PVC and silicone and comply with
UL safety directives. The UL certification
AWM STYLE 20963 80 °C 30 V E63216 is
documented on the cable.
Temperature range
HEIDENHAIN cables can be used:
for rigid configuration –40 to 85 °C
for frequent flexing –10 to 85 °C
Cables with limited resistance to hydrolysis
and microbes are rated for up to 100 °C.
Bending radius
The permissible bending radii Rdepend on
the cable diameter and the configuration:
Electrically permissible speed/
Traversing speed
The maximum permissible shaft speed or
traversing velocity of an encoder is derived
from
the mechanically permissible shaft
speed/traversing velocity (if listed in
Specifications)
and
the electrically permissible shaft speed/
traversing velocity.
For encoders with sinusoidal output
signals, the electrically permissible shaft
speed/traversing velocity is limited by
the –3dB/ –6dB cutoff frequency or the
permissible input frequency of the
subsequent electronics.
For encoders with square-wave signals,
the electrically permissible shaft speed/
traversing velocity is limited by
– the maximum permissible scanning/
output frequency fmax of the encoder
and
– the minimum permissible edge
separation afor the subsequent
electronics.
For angular/rotary encoders
nmax =
fmax · 60 · 103
For linear encoders
vmax = fmax · SP· 60 · 10–3
where
nmax: Electrically permissible shaft
speed in rpm,
vmax: Electrically permissible traversing
velocity in m/min
fmax: Maximum scanning/output
frequency of the encoder or
input frequency of the
subsequent electronics in kHz,
z: Line count of the angular/
rotary encoder per 360 °
SP: Signal period of the linear
encoder in µm
Typically 500 ms
UPP
Initial transient of the
power supply voltage, e.g. 5 V ± 5 %
Power supply
The encoders require a stabilized dc
voltage UP as power supply. The respective
specifications state the required power
supply and the current consumption. The
permissible ripple content of the dc voltage
is:
High frequency interference
UPP < 250 mV with dU/dt > 5 V/µs
Low frequency fundamental ripple
UPP < 100 mV
The values apply as measured at the
encoder, i.e., without cable influences. The
voltage can be monitored and adjusted with
the device’s sensor lines. If a controllable
power supply is not available, the voltage
drop can be halved by switching the sensor
lines parallel to the corresponding power
lines.
Calculation of the voltage drop:
U= 2 · 10–3 ·
where
U:Line drop in V
LC: Cable length in mm
I: Current consumption of the
encoder in mA (see Specifications)
AV: Cross section of power lines
in mm2
LC · I
56 · AV
HEIDENHAIN
cables
Cross section of power lines AV
1 VPP/TTL/HTL 11 µAPP EnDat/SSI
3.7 mm 0.05 mm2 – –
4.5/5.1 mm 0.14/0.052) mm2 0.05 mm2 0.05 mm2
6/101)mm 0.19/ 0.143) mm2 – 0.08 mm2
8/141)mm 0.5 mm2 1mm2 0.5 mm2
HEIDENHAIN
cables
Rigid configuration
Frequent
flexing
3.7mm R 8mm R 40 mm
4.5mm
5.1mm
R 10 mm R 50 mm
6mm R 20 mm R 75 mm
8mm R 40 mm R 100 mm
10mm1) R 35 mm R 75 mm
14mm1) R 50 mm R 100 mm 1) Metal armor
2) Only on length gauges
3) Only for LIDA 400
z
Rigid configuration
Frequent flexing
Frequent flexing
71
Reliable Signal Transmission
Electromagnetic compatibility/
CE compliance
When properly installed, HEIDENHAIN
encoders fulfill the requirements for electromagnetic
compatibility according to
89/336/EEC with respect to the generic
standards for:
Noise immunity IEC 61000-6-2:
Specifically:
– ESD IEC 61000-4-2
– Electromagnetic fields IEC 61000-4-3
– Burst IEC 61000-4-4
– Surge IEC 61000-4-5
– Conducted
disturbances IEC 61000-4-6
– Power frequency
magnetic fields IEC 61000-4-8
– Pulse magnetic fields IEC 61000-4-9
Interference IEC 61000-6-4:
Specifically:
– For industrial, scientific and medical
(ISM) equipment IEC 55011
– For information technology
equipment IEC 55022
Transmission of measuring signals—
electrical noise immunity
Noise voltages arise mainly through
capacitive or inductive transfer. Electrical
noise can be introduced into the system
over signal lines and input or output
terminals. Possible sources of noise are:
Strong magnetic fields from transformers
and electric motors
Relays, contactors and solenoid valves
High-frequency equipment, pulse
devices, and stray magnetic fields from
switch-mode power supplies
AC power lines and supply lines to the
above devices
Isolation
The encoder housings are isolated against
all circuits.
Rated surge voltage: 500 V
(preferred value as per VDE 0110 Part 1)
Protection against electrical noise
The following measures must be taken to
ensure disturbance-free operation:
Use only original HEIDENHAIN cables.
Watch for voltage attenuation on the
supply lines.
Use connectors or terminal boxes with
metal housings. Do not conduct any
extraneous signals.
Connect the housings of the encoder,
connector, terminal box and evaluation
electronics through the shield of the
cable. Connect the shielding in the area
of the cable inlets to be as induction-free
as possible (short, full-surface contact).
Connect the entire shielding system with
the protective ground.
Prevent contact of loose connector
housings with other metal surfaces.
The cable shielding has the function of
an equipotential bonding conductor. If
compensating currents are to be expected
within the entire system, a separate
equipotential bonding conductor must be
provided.
See also EN 50178/ 4.98 Chapter 5.2.9.5
regarding “protective connection lines
with small cross section.”
Connect HEIDENHAIN position encoders
only to subsequent electronics whose
power supply is generated through double
or strengthened insulation against line
voltage circuits. See also IEC 364-4-41:
1992, modified Chapter 411 regarding
“protection against both direct and indirect
touch” (PELV or SELV).
Do not lay signal cables in the direct
vicinity of interference sources (inductive
consumers such as contacts, motors,
frequency inverters, solenoids, etc.).
Sufficient decoupling from interferencesignal-
conducting cables can usually be
achieved by an air clearance of 100 mm
(4 in.) or, when cables are in metal ducts,
by a grounded partition.
A minimum spacing of 200 mm (8 in.) to
inductors in switch-mode power supplies
is required. See also EN 50178 /4.98
Chapter 5.3.1.1 regarding cables and
lines, EN 50174-2 /09.01, Chapter 6.7
regarding grounding and potential
compensation.
When using multiturn encoders in
electromagnetic fields greater than
10 mT, HEIDENHAIN recommends
consulting with the main facility in
Traunreut.
Both the cable shielding and the metal
housings of encoders and subsequent
electronics have a shielding function. The
housings must have the same potential
and be connected to the main signal ground
over the machine chassis or by means of a
separate potential compensating line.
Potential compensating lines should have a
minimum cross section of 6 mm2 (Cu).
Minimum distance from sources of interference
72
Evaluation and Display Units
ND 281B
Position display unit
The ND 281B position display unit contains
special display ranges for angle measurement.
You can directly connect incremental
angle encoders with 1-VPP output signals
and any line count up to 999999 signal
periods per revolution. The display value is
available via the RS-232-C/V.24 interface for
further processing or print-out.
ND 281B
Input signals 1 VPP 11 µAPP
Encoder inputs Flange socket, 12-pin female Flange socket, 9-pin female
Input frequency Max. 500 kHz Max. 100 kHz
Max. cable length 60 m 30 m
Signal subdivision Up to 1024-fold (adjustable)
Display step
(adjustable)
Decimal degrees:0.1° to 0.000002°
Degrees, minutes, seconds:to 1"
Display range
(adjustable)
0 to 360°
–180° .... 0 ..... +180°
0 to ± max. display range
Features Sorting and tolerance check mode with two limit values
Display stop
Two switching limits
Reference-mark evaluation with REF
External operation Zero reset, preset and latch command
Interface RS-232-C/V.24; max. 38400 baud
IBV 600 series
Interpolation and digitizing electronics
Interpolation and digitizing electronics
interpolate and digitize the sinusoidal output
signals ( 1 VPP) from HEIDENHAIN
encoders up to 400-fold, and convert them
to TTL square-wave pulse sequences.
IBV 610 IBV 650 IBV 660
Input signals 1 VPP
Encoder inputs Flange socket, 12-pin female
Interpolation (adjustable) 5-fold
10-fold
50-fold 25-fold
50-fold
100-fold
200-fold
400-fold
Input frequency/
minimum edge separation
(adjustable)
5-fold interpolation
200 kHz/0.25 µs
100 kHz/0.5 µs
50 kHz/1 µs
25 kHz/2 µs
10-fold interpolation
200 kHz/0.125 µs
100 kHz/0.25 µs
50 kHz/0.5 µs
25 kHz/1 µs
40 kHz/0.125 µs
20 kHz/0.25 µs
10 kHz/0.5 µs
5 kHz/1 µs
Depending on
interpolation:
100 kHz/0.1 µs
to
0.78 kHz/0.8 µs
Output signals Two TTL square-wave pulse trains Ua1 and Ua2
and their inverted signals and
Reference pulse Ua0 and
Interference signal
Power supply 5 V ± 5% For more information, see the Interpolation
and Digitizing Electronicscatalog.
For more information, see the Numerical
Displays for Length and Anglecatalog.
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IK 220
Universal PC counter card
The IK 220 is an expansion board for ATcompatible
PCs for recording the measured
values of two incremental or absolute
linear or angle encoders. The subdivision
and counting electronics subdivide the
sinusoidal input signals to generate up to
4096 measuring steps per input signal
period. A driver software package is
included in delivery.
IK 220
Input signals
(switchable)
1 VPP 11 µAPP EnDat SSI
Encoder inputs 2 D-sub connectors (15-pin), male
Input frequency (max.) 500 kHz 33 kHz –
Cable lengths (max.) 60 m 10 m
Signal subdivision
(signal period: meas. step) Up to 4096-fold
Data register for measured
values (per channel)
48 bits (44 bits used)
Internal memory For 8192 position values
Interface PCI bus (plug and play)
Driver software and
demonstration program
For WINDOWS NT/95/98
in VISUAL C++, VISUAL BASIC and
BORLAND DELPHI
Dimensions Approx. 190 mm × 100 mm For more information, see the IK 220
product informationsheet.
Electronics
74
head needs to be aligned very accurately
during mounting. HEIDENHAIN offers
various measuring and testing equipment
for checking the quality of the output signals.
With modular angle encoders the scanning
head moves over the graduation without
mechanical contact. Thus, to ensure
highest quality output signals, the scanning
PWT 18
Encoder input 1 VPP
Features Measuring the signal amplitude
Tolerance of signal shape
Amplitude and position of the reference-mark signal
Power supply Via power supply unit (included)
Dimensions 114mm x 64mm x 29mm
for Absolute Angle Encoders
The PWM 9 is a universal measuring device
for checking and adjusting HEIDENHAIN
incremental encoders. There are different
expansion modules available for checking
the different encoder signals. The values
can be read on an LCD monitor. Soft keys
provide ease of operation.
IK 115
Encoder input EnDat (absolute value or incremental signals) or SSI
Interface ISA bus
Application software Operating system: Windows 95/98
Functions: Position value display
Counter for incremental signals
EnDat functions
Dimensions 158 mm x 107 mm
The PWT 18 is a simple adjusting aid for
HEIDENHAIN incremental encoders. In a
small LCD window the signals are shown
as bar charts with reference to their
tolerance limits.
The IK 115 is an adapter card for PCs for
inspecting and testing absolute
HEIDENHAIN encoders with EnDat or SSI
interface. Parameters can be read and
written via the EnDat interface.
HEIDENHAIN Measuring Equipment
for Incremental Angle Encoders
PWM 9
Inputs Expansion modules (interface boards) for 11 µAPP; 1 VPP;
TTL; HTL; EnDat*/SSI*/commutation signals
*No display of position values or parameters
Features Measures signal amplitudes, current consumption,
operating voltage, scanning frequency
Graphically displays incremental signals, (amplitudes,
phase angle and on-off ratio) and the reference mark signal
(width and length)
Display symbols for reference mark, fault detection
signal, counting direction
Universal counter, interpolation selectable
from 1 to 1024-fold
Adjustment aid for exposed encoders
Outputs Inputs are fed through for subsequent electronics
BNC sockets for connection to an oscilloscope
Power supply 10 to 30 V, max 15W
Dimensions 150 mm × 205 mm × 96 mm
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