Modular Angle
Encoders
With Circular Scale

03/2023

Modular angle encoders with circular scale

Modular angle encoders with a circularscale are deployed on machines and auto­mated systems requiring high measurement
accuracy. Typical applications include thefollowing:• Production and measurement equipmentin the semiconductor industry• PCB assembly machines• Ultra-precision equipment such as
diamond lathes for optical components• High-accuracy machine tools• Measuring machines, comparators,
measuring microscopes, and otherprecision measuring devices• Direct drive motors

Table of contents

Mechanical design
Modular angle encoders consist of a circularscale and a scanning head that operate
without mechanical contact. For highaccuracy, the mounting surface for thecircular scale must exhibit high flatness.

Overview

4Angle encoders from HEIDENHAIN
Selection guide

Modular angle encoders with optical scanning and scale drum

6

Measuring standard

8

Absolute measuring method

8

Incremental measuring method8

Photoelectric scanning principle

10

Technical features and mounting information
Measuring principles

Measurement accuracy

12

Reliability

16

Signal-quality indicator

18

Mechanical design types and mounting

19

Cable outlets and connectors for ERP 1000 and ERO 2000

22

Specifications
Modular angle encoders with optical scanning

Series or model

Graduation accuracy

ERP 880±0.9”

24

ERP 1000 series

Down to ±0.9”

26

ERO 2000 series

Down to ±8.0”32Incremental signals» 1 VPP

36

« TTL

36

EnDat

37

Electrical connection
Interfaces

Position values

Information about the following topics isavailable upon request or online atwww.heidenhain.com:• Angle encoders with integral bearing• Modular angle encoders with scale drumor scale tape
• Rotary encoders• Encoders for servo drives• Linear encoders for numerically controlledmachine tools• Signal converters• HEIDENHAIN controls

2Further information:
This brochure supersedes all previous
editions, which thereby become invalid.
The basis for ordering from HEIDENHAIN
is always the brochure edition valid when
the order is placed.
Standards (ISO, EN, etc.) apply only
where explicitly stated in the brochure.

For detailed descriptions of all available
interfaces, as well as general electricalinformation, please refer to the Interfacesof HEIDENHAIN Encoders brochure(ID 1078628-xx).
For the required cables, please refer tothe Cables and Connectors brochure(ID 1206103-xx).

Pin layout

38

Testing equipment and diagnostics

41

Angle encoders from HEIDENHAIN

Modular angle encoders with opticalscanning
The ERP, ERO, ERA and ECA modular
angle encoders are particularly well suitedfor high-accuracy applications with low
installation space. Particular benefits:• Wide hollow-shaft diameter (of up to
10 m with a scale tape)• High shaft speeds of up to 20 000 rpm• No additional starting torque fromshaft seals• Segment solutions• Also available with functional safety

Angle encoders are found in applications
requiring precision angular measurement
at accuracies within several arc seconds.
Examples:• Rotary tables on machine tools• Swivel heads on machine tools• C axes on lathes• Measuring machines for gears• Printing units of printing machines• Spectrometers• Telescopes• Laser trackers• Rotary tables on measuring machines• Rotary tables on wafer-handlingmachinesetc.

ECA 4000 absolute angle encoderwith scale drum

In contrast, rotary encoders are used inapplications where accuracy requirements
are less stringent (e.g., in automation,
motors and many other applications).

Modular angle encoders with opticalscanning are available with various
graduation carriers:• ERP/ERO: Glass circular scale with hub• ERA/ECA 4000: Steel drum
• ERA 7000/8000: Steel scale tape
Because these angle encoders do not comewith an enclosure, the required degree ofprotection must be ensured through proper
installation.

ERO 2000 incremental angle encoderwith scale drum

Angle encoders differ in terms of thefollowing physical design characteristics:
Sealed angle encoders with a hollow
shaft and stator coupling
The stator coupling is designed so that the
coupling absorbs only the torque arisingfrom bearing friction, especially during
angular acceleration of the shaft. These
angle encoders therefore provide excellent
dynamic performance. Due to the stator
coupling, the stated system accuracy
includes the error of the shaft coupling.
The RCN, RON and RPN angle encoders
have an integrated stator coupling, while
the ECN is externally mounted.
Other benefits:• Compact size for limited installation space• Hollow shaft diameters of up to 100 mm• Easy installation• Also available with functional safety

4

ECM 2000 absolute angle encoder

Modular angle encoder with magnetic
scanning
Thanks to their robust design, the ERM
and ECM modular angle encoders arehighly immune to cooling lubricant andcontamination in production machines.
They are ideal for medium to high accuracy
requirements and low installation space:• Large shaft diameters• High shaft speeds of up to 60 000 rpm• No additional starting torque fromshaft seals• High immunity to contamination• Available with functional safety

RCN 8000 absolute angle encoder5

Selection guide
Modular angle encoders with optical scanning and scale drum

SeriesVersion and mounting Overall dimensions
in mm

Diameter
D1/D2

Accuracy ofgraduation

Mechanicallypermissible
speed1)Signalperiods per
revolution

Reference
marks

Interface

Model

Page

D1:	  51.2 mm
D2: 200 mm±0.9”

 1000 rpm

180 000One» 1 VPPERP 880

24

ERP 880

Phase grating on glass
disk with hub; screwed
onto front of shaft

 D2

Angle encoders with graduation on circular scale

ERP 880

 D1

ERP 1000SUPRADUR graduation
on glass

26

 

12.7

ERO 2000

OPTODUR graduation
on glass disk with hub;screwed onto front of
shaft

26

D1: 104 mm
D2: 151 mm±0.9”/1.5”

 950 rpm

63 000

D1:	  62 mm
D2: 109 mm±1.8”

 1200 rpm

50 000

D1:	  32 mm
D2:	  75 mm±3”

 2000 rpm

30 000

D1:	  13 mm
D2:	  57 mm±4”

 2600 rpm

23 000

D1:	  5 mm
D2:	  30 mm±8”

 14 000 rpm

4096

D1:	  –
D2:	  18.6 mm±10”

 24 000 rpm

2500

One

» 1 VPP TTL
EnDat 2.2

ERP 1080
ERP 1070
ERP 1010

26

ERP 1000One» 1 VPPERO 2080

32

6.8

 

1)
2)

6

ERO 2000

May be limited during operation due to electrically permissible shaft speed
Through integrated interpolation

7

Measuring principles

Measuring standard
HEIDENHAIN encoders with opticalscanning incorporate measuring standardsof periodic structures known as graduations.
These graduations are applied to a carrier
substrate made of glass or steel. For
encoders with long measuring lengths,
steel tape is used as the scale substrate.
HEIDENHAIN manufactures the precision
graduations in specially developed,
photolithographic processes.
• AURODUR: matte-etched lines on agold-plated steel tape; typical grating
period: 40 µm• METALLUR: contamination-tolerant
graduation consisting of metal lines ongold; typical grating period: 20 μm• DIADUR: extremely robust chromiumlines on glass (typical grating period:
20 μm), or three-dimensional chromium
structures (typical grating period: 8 μm)
on glass• SUPRADUR phase grating: opticallythree-dimensional, planar structure;
particularly tolerant to contamination;
typical grating period: 8 μm and finer• OPTODUR phase grating: opticallythree-dimensional, planar structure withparticularly high reflectance; typicalgrating period: 2 μm and finer

Absolute measuring method
In the absolute measuring method, theposition value is available immediately upon
encoder switch-on and can be requestedby the downstream electronics at any time.
There is therefore no need to search forthe reference position by jogging the axes.
The absolute position information is readfrom the circular scale, which is designedwith a serial absolute code structure. The
code structure is unique over one revolution.
A separate incremental track is read withthe single-field scanning principle andinterpolated for the position value.

Incremental measuring method
In the incremental measuring method,
the graduation is a periodic grating
structure. The position information is
obtained through counting the individual
increments (measuring steps) starting ata freely selectable point of origin. Since
position measurement requires anabsolute point of reference, the measuring
standard features an additional track
containing a reference mark. The absolute
position on the scale, established by thereference mark, is gated with exactly one
measuring step.
The reference mark must therefore be
traversed before an absolute point ofreference can be established or before themost recently selected reference point isrefound.

In some cases, this may require rotation
by up to 360°. To simplify reference runs,
many HEIDENHAIN encoders feature
distance-coded reference marks: thereference-mark track has multiple referencemarks at different defined distances. The
downstream electronics determine theabsolute reference point after just twoneighboring reference marks have been
traversed; in other words, after just a few
degrees of rotational motion (see “Nominal
increment N” in the table).
With distance-coded reference marks,
the absolute reference is determined bycounting the increments between two
reference marks.

Line count z

Number ofreference marks

Nominal incrementN

36 00018 000

72
36

10°
20°

Along with these very fine grating periods,
these processes permit a high definitionand homogeneity of the line edges.
Together with the photoelectric scanning
method, this high edge definition is aprecondition for the high quality of theoutput signals.
The master graduations are manufactured
by HEIDENHAIN on custom-built highprecision dividing engines.

Circular scale with serial absolute track and incremental trackZeroposition

Schematic representation of a circular scale with distance-coded referencemarks

DIADUR, AURODUR and METALLUR areregistered trademarks of DR. JOHANNESHEIDENHAIN GmbH, Traunreut.

8Absolute and incremental circular scales and scale drums

9

Photoelectric scanning

Most HEIDENHAIN encoders utilize thephotoelectric scanning principle. Photo­
electric scanning is touchless and therefore
does not induce wear. This method detects
even extremely fine graduation lines down
to a width of only a few micrometers andgenerates output signals with very small
signal periods.
The finer the grating period of a measuring
standard is, the greater the effect ofdiffraction on photoelectric scanning.
HEIDENHAIN angle encoders use twoscanning principles:• The imaging scanning principle forgrating periods of 20 µm and 40 µm• The interferential scanning principle
for very fine grating periods of, forexample, 8 µm

Imaging scanning principle
Put simply, the imaging scanning principle
uses projected-light signal generation:
two gratings with equal or similar grating
periods—the scale and the scanning
reticle—are moved relative to each other.
The carrier material of the scanning reticle
is transparent, whereas the graduation of
the measuring standard may be applied toa transparent material or to a reflective
material.

Signal period
360° elec.

When parallel light passes through a
grating structure, light and dark fields areprojected at a certain distance. At thislocation there is an index grating. When thetwo gratings move relative to each other,
the incident light is modulated: If the gaps
are aligned, light passes through. If thelines of one grating coincide with the gapsof the other, no light passes through. A
photocell array converts these variations inlight intensity into electrical signals. The
specially structured grating of the scanning
reticle filters the light to generate nearlysinusoidal output signals.

The sensor generates four nearlysinusoidal current signals (I0°, I90°, I180°,
and I270°), phase-shifted to each otherby 90° elec. These scanning signals do
not initially exhibit symmetry about thezero line. For this reason, the photocells
are connected in anti-parallel, thereby
producing two 90° elec. phase-shifted
output signals, I1 and I2, which aresymmetrical about the zero line.
In the X/Y representation on an
oscilloscope, the signals form a
Lissajous figure. Ideal output signals
appear as a centered circle. Deviationsin the circular form and position arecaused by position errors and therefore
go directly into the result of measure­ment. The size of the circle, whichcorresponds to the amplitude of theoutput signal, can vary within certain
limits without influencing themeasuring accuracy.

The smaller the graduation period of thegrating structure, the closer and more tightly
toleranced the gap must be between thescanning reticle and the scale. In encoders
that use the imaging scanning principle,
workable mounting tolerances are
attainable starting at a minimum grating
period of 10 μm.
The ERO angle encoders, for example,
operate according to the imaging scanningprinciple.

90°
elec.

A step grating is used as the measuring
standard: reflective lines with a height of
0.2 µm are applied to a flat, reflective
surface. In front of this is the scanning
reticle—a transparent phase grating withthe same grating period as the scale.
When a light wave passes through thescanning reticle, it is diffracted into threepartial waves of the orders +1, 0, and –1,
with nearly equal luminous intensity. The
waves are diffracted by the scale such thatmost of the luminous intensity is found in
the reflected diffraction orders +1 and –1.
These partial waves meet again at thephase grating of the scanning reticle,
where they are diffracted again andinterfere. This produces essentially threewaves that leave the scanning reticle atdifferent angles. Photocells convert thesealternating light intensities into electricalsignals.

When there is relative motion between thescale and the scanning reticle, the diffracted
wavefronts undergo a phase shift: move­
ment by the amount of one grating period
shifts the positive first-order diffraction
wavefront by one wavelength in the positive
direction, while the negative first-orderdiffraction wavefront is displaced by one
wavelength in the negative direction. Since
the two waves interfere with each otherupon exiting the phase grating, thesewaves are shifted relative to each other by
two wavelengths. This results in two signal
periods when there is relative motion ofjust one grating period.
Interferential encoders use grating periodsof, for example, 8 µm, 4 µm, or finer. Theirscanning signals are largely free of harmonics
and can be highly interpolated. These
encoders are therefore especially suited forsmall measuring steps and high accuracy.
The ERP angle encoders, for example,
operate according to the interferential
scanning principle.

Phase shift
X/Y representation of the output signals

Imaging scanning principle

Interferential scanning principle
The interferential scanning principle uses
the diffraction and interference of light onfinely divided gratings in order to produce
the signals from which motion ismeasured.

Interferential scanning principle (optical diagram)
C Grating periody 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

Measuring standard

LED light
sourceCondenser

Scanning reticle

Scanning reticle
transparent phase grating

Photocell array–10+1Orders of diffraction

10

Measuring standard
phase grating

11

Measurement accuracy

The accuracy of the graduation is indicatedby the uncompensated maximum valueof the baseline error. This accuracy is
ascertained under ideal conditions via
measurement of the position error by meansof a serially produced scanning head. The
distance between the measuring points is
equivalent to the integer multiple of thesignal period. As a result, the interpolation
error has no effect. The accuracy of thegraduation a defines the upper limit of thebaseline error within any section of up to360°. For special encoders, an additional
baseline error is stated for defined angularintervals of the graduation.

The encoder-specific error is given in theSpecifications:• The graduation accuracy• The Interpolation error within one signal
period• The position noise
The graduation accuracy
The accuracy ±a of the graduation resultsfrom its quality. This includes:• The homogeneity and period definitionof the graduation• The alignment of the graduation on thegraduation carrier• The stability of the graduation carrier, inorder to also ensure accuracy in themounted condition
Interpolation error within one signal
periodThe interpolation error within one signal
periods ±u is primarily influenced by:• The fineness of the signal period• The homogeneity and period definitionof the graduation• The quality of the scanning filter
structures• The characteristics of the sensors• The quality of the signal processing
electronics

Interpolation errors within one signal period
already become apparent in very small
rotational motions and in repeatedmeasurements. They especially lead tospeed ripples in the speed control loop.
Position noise
Position noise is a random process leading
to unpredictable position errors. The position
values are grouped around an expectedvalue in the form of a frequency distribution.
The amount of position noise depends
on the signal processing bandwidths
necessary for forming the position values.
It is ascertained within a defined timeinterval and is stated as a product-specific
RMS value.
In the speed control loop, position noise
influences the speed stability at low
rotational speeds.

Application-dependent error

The quality of the mounting and adjustmentof the scanning head, in addition to thegiven encoder-specific error, normally has asignificant effect on the accuracy that canbe achieved by encoders without integral
bearings. Of particular importance are themounting eccentricity of the graduationand the radial runout of the measured
shaft. The application-dependent error
values must be measured and calculated
individually in order to evaluate the overall
accuracy.
In contrast, the specified system accuracy
for encoders with integral bearing alreadyincludes the error of the bearing and theshaft coupling (see the Angle Encoders
with Integral Bearing brochure).

Error due to eccentricity of thegraduation relative to the bearing
Mounting-related eccentricity between thegraduation and the bearing can be expectedduring mounting of the disk/hub assembly.
In addition, dimensional and form error of
the customer’s shaft can result in added
eccentricity. The following relationship exists
between the eccentricity e, the graduation
diameter D, and the measuring error ¹j(see figure below):¹j = ±412 ·¹j =	Measurement error in ” (arc seconds)
e =	Eccentricity of the scale drum relative
to the bearing in µm (1/2 radial
runout)
D = Graduation diameter in mm
M = Center of graduationj = "True" anglej‘ = Scanned angle

Baseline error within a
specified angular interval

Position 

12Interpolation error Baseline error1 ±2.8”146.5

Graduation diameter D for:ERP 880

D = 126 mm

ERP 1000

D = 52.5 mm
D = 71 mm
D = 104.5 mm
D = 146.5 mm

ERO 2000

D = 26.7 mm
D = 16.3 mm

Frequency density

Interpolation error u within one signal period

Signal level Position error Interpolation error
within one signal
period¹j = ±412 ·Position noiseTime 

Graduation accuracy within one revolutioneDCalculation example:
ERP 1000 angle encoder with drum
diameter of 146.5 mm, radial runout of the
disk/hub assembly 2 µm ( eccentricity of
1 µm)

RMS

These factors can be divided into encoderspecific error and application-dependent
factors. All individual factors of influencemust be considered in order to assess theattainable overall accuracy.

Encoder-specific error

Position error 

The accuracy of angular measurement ismainly determined by:• The quality of the graduation• The stability of the graduation carrier• The scanning quality• The quality of the signal processing
electronics• The eccentricity of the graduation relative
to the bearing• The bearing error• The coupling to the measured shaft

Scanning unit

Interpolation
error

Signal period
360 °elec.

The eccentricity of thegraduation relative tothe bearing

13

Calibration chart

Radial runout error of the bearing
The function for finding the measurement
error ¹j also applies to the radial runout
error of the bearing when the eccentricity(half of the displayed radial runout error) is
entered for e. The mechanical complianceof the bearing under radial shaft loads
causes similar errors.
Deformation of the graduation resulting
from mounting
The profile, reference surfaces, position of
the graduation relative to the mounting
surface, threaded holes, etc. of the disk/
hub assemblies are all designed so that themounting and operation only marginallyinfluence the accuracy of the encoders.

Geometric and diameter errors of the
bearing surface (for TKN ERP 1002)
Geometric errors of the bearing surface
can affect the attainable system accuracy.
The segment solutions exhibit additional
angular error ¹j if the nominal mounting
diameter is not precisely complied with:¹j = (1 – D‘/D) · j · 3600
Where
¹j = Error for segment in arc seconds
j = Segment angle in degrees
D = Nominal mounting diameter
D’ = Actual mounting diameter
This error can be eliminated if the signal
period per 360° z’ that is valid for the actual
mounting diameter D’ can be entered into
the controller. The following relationship isvalid:z‘ = z · D‘/D
where 	zz‘				

= Nominal signal period
per 360°= Actual signal period
per 360°

Compensation possibilities
The mounting eccentricity of the graduationand the radial runout of the measured shaft
cause a large share of the applicationdependent error. A common and effective
method of eliminating this error is to mount
two or even more scanning heads at equal
distances around the graduation carrier. The
downstream electronics mathematicallycombine the individual position values.

For all angle encoders from HEIDENHAIN,
proper function is checked and accuracy ismeasured before delivery. The accuracy of
the angle encoders is determined during
traverse over one revolution. The numberof measuring positions is selected todetermine very exactly not only the longrange error, but also the interpolation error
within one signal period. Errors resulting
from mounting are not included.

The EIB 1500 from HEIDENHAIN is anelectronics unit suitable for mathematicallycombining the position values from twoscanning heads in real time and without
negative influences on the control loop
(see Evaluation and display units).

The Quality Inspection Document
confirms the specified graduation accuracyof each encoder. The calibration standards
ensure the traceability—as required by
EN ISO 9001—to recognized national orinternational standards.

The accuracy improvement actuallyattained by this in practice strongly
depends on the installation situation andthe application. In principle, all eccentricity
errors (reproducible errors due to mounting
errors, non-reproducible errors due to radial
eccentricity of the bearing) as well as all
uneven harmonics of the graduation error
are eliminated.

For the ERP and ERO encoder series, acalibration chart documents the ascertained
position error. It also specifies themeasuring parameters and the measure­ment uncertainty.

The angle actually traversed in segment
solutions should be measured with acomparative encoder, such as an angle
encoder with an integral bearing.

Angular error resulting from variations in the mounting diameter

Qualitätsprüfbescheinigung

Quality Inspection Document

TKN ERP 1000
ID 1126369-06
SN 639539006

1

Temperature range
The angle encoders are inspected at areference temperature of 22 °C. This is
the temperature at which the systemaccuracy provided in the calibration chart isvalid.

2

Position calculation of two scanning heads in order to compensate for
eccentricity and radial runout

Segment version

For testing and calibration purposes,
modular angle encoders with circularscale are mounted at HEIDENHAIN in
exactly the same way as in the application
later. This ensures that it is possible toapply the accuracy determined at
HEIDENHAIN exactly to the machine.

Calibration chart using the example of
the ERP 1000 scale drum
1	Graphic representation of the graduationerror
2 Result of calibration

Segment

Center of graduation
ERP/ERO

14

15

The ERP 1000 and ERO 2000 encoders
are equipped with the HSP 1.0 signal
processor ASIC from HEIDENHAIN. This
ASIC continuously monitors the scanningsignal and compensates nearly completely
for fluctuations in signal amplitude. If thesignal amplitude decreases as the result ofcontamination on the scanning reticle ormeasuring standard, the ASIC reacts byincreasing the LED current. The ensuingincrease in LED light intensity barely raises
the noise level, even in the case of strong
signal stabilization. As a result, contamination
has only a very slight influence on inter­
polation errors and the position noise.

16

1.2

In the OPTODUR and SUPRADUR
processes, a transparent layer is first
applied onto the reflective primary layer.
For creating an optically three-dimensional
phase grating, an extremely thin, hard
chromium layer is applied at a thicknessof only a few nanometers. Measuring
standards with OPTODUR or SUPRADUR
graduations have proven to be particularlyrobust and insensitive to contamination
because the low height of their structure
leaves practically no surface for dust, dirt,
or water particles to accumulate.

1.0
0.8
0.6
0.4
0.2
0
Fingerprint

Wire

Oil

0.2
0.1
0
-0.1
-0.2
0

5

10

15

20

25

30

35

40

45

Position in µm With HSP 1.0 signal processing ASIC
Without HSP 1.0 signal processing ASIC

Measuring standard with contamination and the associated signal amplitudes with conventionalscanning and scanning with the HSP 1.0 signal processing ASIC

Workable mounting tolerances
Very small signal periods usually comewith very narrow mounting tolerances forthe gap between the scanning head andscale tape. This is the result of diffraction
caused by the grating structures. Suchdiffraction can lead to a signal attenuationof 50% upon a gap change of only ±0.1 mm.
The interferential scanning principle andinnovative index gratings on encoders
that use the imaging principle allow for
workable mounting tolerances despite tiny
signal periods.
The mounting tolerances of modular angle
encoders with circular scale from HEIDEN­
HAIN have minimal influence on the output
signals. In particular, the specified distancetolerance between the circular scale andscanning head (scanning gap) causes only
negligible change in the signal amplitude.
During operation, the reliability and stabilityof the signals are additionally improved by
the HSP 1.0. The two diagrams illustrate
the correlation between the scanning gap
and signal amplitude for the encoders of
the ERP 1000 and ERO 2000 series.

OPTODUR
SUPRADUR
Reflective layer

Transparent
layer

Reflective
primary layer

Substrate

Signal amplitude in % 

The large scanning field further reduces
the sensitivity to contamination. Dependingon the nature of the contamination, thisfeature can even prevent encoder failure.
The encoders continue to provide highquality signals even if the contamination
comes from printer’s ink, PCB dust, wateror oil and is up to 3 mm in diameter. The
position errors per revolution remain far
below the specified accuracy.

Durable measuring standards
Due to their exposed design, the measuring
standards of modular angle encoders
with circular scale are less protected fromtheir environment. For this reason, HEIDEN­
HAIN always uses tough graduations
manufactured in special processes.

120
100
80
60

Mounting tolerance
ERP 1000

40
20
0

0.35

0.4

0.45

0.5

= During mounting (without HSP 1.0)
= During operation (with HSP 1.0)

Signal amplitude in % 

Low sensitivity to contamination
Both the high quality of the grating and thescanning method are responsible for theaccuracy and reliability of the encoders.
Encoders from HEIDENHAIN operate withsingle-field scanning. Only one scanningfield is used to generate the scanningsignals. Local contamination on themeasuring standard (e.g., fingerprints or oil
accumulation) influences the light intensityof the signal components, and thereforeof the scanning signals, in equal measure.
The output signals do change in theiramplitude, but not in their offset and phase
position. The signals remain highlyinterpolable, and the position error per
signal period remains small.

Interpolation error andnoise in µm 

Modular angle encoders with opticalscanning from HEIDENHAIN are optimized
for use on fast, precise machines. Even
with their exposed mechanical design,these encoders are highly immune tocontamination, ensure high long-term
stability and are fast and easy to mount.

Signal in VPP 

Reliability

0.55

0.6

0.65

Scanning gap in mm 

120
100
80
60
40

Mounting tolerance
ERO 200020
00.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85

= During mounting (without HSP 1.0) Scanning gap in mm 
= During operation (with HSP 1.0)

17

Signal-quality indicator

Mechanical design types and mounting

The ERP 1010 and ERP 1070 modular angle
encoders feature an integrated signal-quality
indicator with a multicolor LED, permitting
fast and easy signal-quality checks during
operation.

The modular angle encoders with circularscale consist of a scanning head and a
disk/hub assembly. The position of thescanning head and graduation relative toeach other is determined solely via themachine guideway. For this reason, themachine must be designed from the very
beginning to meet the following
prerequisites:• The bearing must be designed such thatit meets the accuracy requirements of
the axis and the scanning-gap tolerancesof the encoder, even during operation(see the Specifications).
• The mounting surface for the graduation
carrier must meet the flatness, roundness,radial runout and diameter requirementsof the given encoder.
• To facilitate adjustment of the scanninghead relative to the graduation, thescanning head should be fastened via a
mounting bracket or via appropriate fixed
stops.

This feature provides a number of benefits:• Scanning-signal quality visualization via a
multicolor LED• Continuous monitoring of incremental
signals over the entire angularmeasurement range• Indication of the reference-mark signal
behavior• Quick signal-quality checks in the field
without additional aids

ERP 1010 and ERP 1070:
Signal-quality indicator in the interface
electronics

The built-in signal-quality indicator permits
both a reliable assessment of theincremental signals and inspection of thereference mark signal. The quality of theincremental signals is indicated bydifferent colors. A blue LED indicatestraversal of the reference mark.

LED indicator for incremental signals
LED color

Quality of the scanningsignalsOptimal

AcceptableUnsatisfactory

All modular angle encoders with circularscale are designed such that the specified
accuracy can be reached in the actual
application. The various mounting designs
ensure the highest possible reproducibility.

LED indicator for the reference marksignalWhen the reference mark is traversed,
the LED briefly switches to blue. In the
ERP 1070 encoders, the LED can also be
used for checking the reference marksignal: Out of tolerance In tolerance

LED indicator for control margin
In the encoders with a TTL interface(ERP 1070), a flashing LED (goes briefly
dark every 2.5 s) indicates when thecontrol margin of the scanning ASIC (HSP)
is nearly exhausted. Clean the measuring
standard and the scanning window of thescanning head in compliance with therelevant information in the mounting
instructions. The encoder may also need to
be checked for correct mounting.

Centering the graduation
Since graduations from HEIDENHAIN havea very high degree of accuracy, the attainable
overall accuracy is predominantly affectedby mounting errors (mainly eccentricity
errors). Various possibilities for centering,depending on the encoder and mounting
method, are possible for minimizing theeccentricity errors in practice.
1. Three-point centering
The graduation carrier is centered via threepositions marked on the graduation carrierat 120° increments. As a result, anyroundness errors of the surface on which
the carrier is to be centered do not affectthe exact alignment of the axis center
point.

m = Marks for three-point centering
Three-point centering

2. Optical centering
Graduation carriers made from glass areoften centered with the aid of a micro­
scope. This method uses the clear andunambiguous reference edges or centeringrings on the graduation carriers.
3. Centering with two scanning heads
This strategy is suited for all modular angle
encoders with circular scale. Because
HEIDENHAIN graduations exhibit a longrange characteristic error, and because
the graduation or the position value itself
serves as the reference with this centering
method, this is the most accurate
centering method.

Optical centering

In the encoders with a serial interface(ERP 1010), an error bit is set when a red
LED is displayed. Error bits can be displayedand cleared with the ATS mounting wizard.
Scanning heads
Since final assembly of the modular angle
encoders with circular scale takes place on
the machine, exact mounting of the scanninghead is necessary once the graduation
carrier has been mounted. In order for thescanning head to be exactly aligned, it
must in principle be aligned and adjustablein five axes (see illustration). This adjustment
is greatly facilitated by the design of thescanning heads, with the corresponding
mounting strategy and wide mounting
tolerances.

18

Centering with two scanning heads

19

ERP 880

ERP 1000
ERO 2000

The ERP 880 modular angle encoder
consists of the following components:
scanning unit, disk/hub assembly, and PCB.
Housings for protection from contact orcontamination can be supplied asaccessories.

The ERP 1000 and ERO 2000 modular
angle encoders consist of a scanning head
and a disk/hub assembly or a circular scalewith pin. These are positioned and adjusted
relative to each other on the machine.

0.5 mm
0.5 mmMounting the disk/hub assembly
The disk/hub assembly is pressed onto theshaft axially, centered using the inside
diameter of the hub, and fastened withscrews. The circular scale can be centeredusing a dial indicator on the inside diameterof the hub, or optically using the graduation
track integrated in the circular scale, or
electrically with the aid of a second,
diametrically opposed scanning head.

Mounting the ERP 880
First the scanning unit is mounted on thestationary machine part with an alignment
accuracy to the shaft of ±1.5 µm. Then the
disk/hub assembly is screwed onto thefront of the shaft, and is also aligned with amaximum eccentricity of ±1.5 µm to thescanning unit. Then the PCB is attachedand connected to the scanning unit. Fine
adjustment takes place with “electricalcentering” using the PWM 9 (see HEIDEN­
HAIN measuring equipment) and an
oscilloscope. A housing can protect the
ERP 880 from contamination.
Mounting
the ERP 880(in principle)

Mounting the disk/hub assembly witha centering pin
The TKN ERP 1002 segments feature acentering pin for easy mounting to themating component. This procedure issufficient for application where only small
angles need to be measured. The gap to
the scanning head is adjusted with the aidof a spacer shim (0.5 mm). Each segment
features two threaded holes for attaching.
The TKN ERO 2000 full circles as well as
the TKN ERO 2002 segments feature an
H7 fitting hole for quick and easy mounting.
To increase accuracy, the circular scale canalso be centered optically. For this purpose,the hole in the mating component musthave a larger diameter. The measuring
standard and the mating component must
be connected through an adhesive bond.
A UV-curing adhesive is recommended.

IP40 housing
With sealing ring for IP40 protection
Cable, 1 m, with 12-pin coupling (male)
ID 369774-01
IP64 housing
With shaft sealing ring for IP64 protection
Cable, 1 m, with 12-pin coupling (male)
ID 369774-02

20

Mounting the scanning head
The modular angle encoders must be
precisely adjusted after being installed on
the machine. This adjustment determines
the final accuracy of the encoder. It istherefore advisable to design the machinesuch that this adjustment is as easy andpractical as possible, while also ensuring
the greatest possible degree of mounting
stability. The scanning heads of the ERP 10x0
and ERO 2080 be fastened from the side
as well as from above.

21

Cable outlets and connectors for ERP 1000 and ERO 2000

Cable outlet, straight

Right-side cable outlet

D-sub connector

Left-side cable outlet

Stecker Sub-D, 15-polig

SHR-12V-S connector		

Cable outlet, angled

Right-side cable outlet,
angled (0°)» 1 VPP, TTL, EnDat» 1 VPP

Left-side cableoutlet, angled (0°)

Cable clip
(M3x6 screw)

Cable bend radius R

22

23

ERP 880
Incremental angle encoder for very highaccuracy• High resolution• Protective cover as accessory
ERP 880
Measuring standard

DIADUR phase grating on glass

Signal periods

180 000

Accuracy of graduation±0.9”

Position error per signal
1)
period±0.1”

Reference marksOne

Hub inside diameter

51.2 mm

Mech. permissible speed

 1000 rpm

Moment of inertia-32
1.2 · 10 kgm

Permissible axial motion of
measured shaft

 ±0.05 mm

Interface» 1 VPP

Cutoff frequency
				

–3 dB
–6 dB

 800 kHz 1.3 MHzElectrical connection

With cover: Cable (1 m) with M23 coupling
Without housing: Via 12-pin PCB connector (adapter cable ID 372164-xx)

Cable length 150 m (with HEIDENHAIN cable)

Supply voltage

DC 5 V ±0.5 V

Current consumption

 250 mA (without load)

Vibration 55 Hz to 2000 Hz
Shock 6 ms    50 m/s (EN 60068-2-6)
 1000 m/s2 (EN 60068-2-27)

Operating temperature

0 °C to 50 °C

Protection* EN 60529

Without housing: IP00

Starting torque

–

Mass

3.0 kg2

With housing: IP40

With housing and shaft seal: IP64
0.25 Nm

3.1 kg incl. housing* Please select when ordering
1)	The position error per signal period and the accuracy of the graduation together yield the encoder-specific error; for additional errors
arising from installation and the bearing of the measured shaft, see Measurement accuracy

Radial cable (can also be used axially)
L = Axis of bearing rotationk = Required mating dimensions
1 = Disk-to-scanning-reticle gap
2 = Seal
3 = Space required for service
4 =	Direction of shaft rotation for output signals
according to interface description

24

Scanning position A

25

ERP 1000 series• Very high resolution and accuracy• Low mass and low mass moment of inertia• Consisting of an AK scanning head and TKN circular scale

Mounting adapter

A
Ⓡ
1
2
3
4
5
6
7

= Bearing= Reference mark= Centering collar= Fine adjustment of the scanning head for attainment of
optimal incremental signals= Marks for circular scale centering (3x120°)= Optical centering point= For centering of circular scale with two scanning heads= Positive direction of rotation= Alternative cable outlet and connector are available

LE = Line element (ISO 1101: 2008)
SP = Signal periods

26

A
r
1
2
3
4
5
6

= Bearing= Position of the reference mark= Positive direction of rotation= Fine adjustment of the scanning head for attainment of
optimal incremental signals= Optical center point= Alternative cable outlet and connector are available= Center of rotation= Adjustable

LE = Line element (ISO 1101: 2008)
SP = Signal periods
MR = Measuring range
MR* = Required range for electronic fine adjustment

27

Specifications

Scanning head

AK ERP 1070

Scanning head

AK ERP 1010

Interface« TTL

Interface

EnDat 2.2

Reference mark signal

Square-wave pulse

Ordering designation

EnDat22

Integrated interpolation*

1-fold5-foldClock frequency

 16 MHz

Scanning frequency

 450 kHz 312.5 kHz

Calculation time tcal

 5 µsEdge separation a 0.125 µs

 0.135 µs

Electrical connection*

Electrical connection*

15-pin D-sub connector (male) with 0.5 m/1 m/1.5 m cable, interface electronics in the connector;
cable outlet: left or right and straight or angled

15-pin D-sub connector (male) with 0.5 m/1 m/1.5 m/3 m cable; interface electronics inside the connector;
cable outlet: left or right and straight or angled

Cable lengthWith HEIDENHAIN cable:  100 m; during signal adjustment with the PWM 21:  3 m

Cable lengthWith HEIDENHAIN cable:  20 m; during signal adjustment with the PWM 21:  3 m

Supply voltage

DC 3.6 V to 14 V

Supply voltage

DC 5 V ±0.5 V

Power consumption (max.)

At 3.6 V: 1220 mW; at 14 V: 1430 mW

Current consumption

 300 mA (without load)

Current consumption (typical)

At 5 V: 175 mA (without load)

2)

1)

10-fold

 0.07 µs

25-fold

50-fold

100-fold

500-fold

1000-fold 250 kHz 125 kHz 62.5 kHz  12.5 kHz  6.25 kHz 0.03 µs

1)1)Absolute position value after crossing of the reference mark in “Position value 2”

Scanning head

AK ERP 1080

Scanning head

Generally valid (AK ERP 1070 / AK ERP 1080 / AK ERP 1010)

Interface» 1 VPP

Reference mark signal

Square-wave pulse

Vibration 55 Hz to 2000 Hz
Shock 6 ms

2
 500 m/s (EN 60068-2-6)
2
 1000 m/s (EN 60068-2-27)

Cutoff frequency

 1 MHzOperating temperature–10 °C to 70 °C

Protection

IP50

–3 dB

Electrical connection*

15-pin D-sub connector (male) with 0.5 m/1 m/1.5 m/3 m cable;
12-pin SHR-12V-S connector (female) with 0.5 m/1 m/1.5 m/3 m cable;
cable outlet: left or right and straight or angled

Cable lengthWith HEIDENHAIN cable:  20 m; during signal adjustment with the PWM 21:  3 m

Supply voltage

DC 5 V ±0.5 V

Current consumption

 150 mA (without load)

Mass		
						Scanning head
ConnectorCable 5 g (without cable)
 75 g 22 g/m* Please select when ordering1)	Suitable for applications that measure the time between individual TTL output signal clock edges;
non-clocked output signals keep edge jitter low
2)
Maximum scanning frequency during referencing: 70 kHz

28

29

Circular scale

TKN ERP 1000 (full circle)

Circular scale

TKN ERP 1002 (segment)

Measuring standard

OPTODUR graduation on glass

Measuring standard

OPTODUR graduation on glass

Signal periods*

23 00030 00050 00063 000Signal periods*

23 00030 00050 00063 000

±4”

±3”

±1.8”

±1.5” or ±0.9”±0.06”±0.04”±0.025”±0.02”

 ±0.6”/10°

 ±0.5”/10° or ±0.4”/10°

Position error per signal
periodPosition noise RMS(1 MHz)0.006”

0.004”

0.003”

0.002”

1)
Positions/rev. over 360°

376 832 000

491 520 000

819 200 000

1 032 192 000

Measuring step

0.0034”0.0026”0.0016”0.0013”

Reference marks

One

Measuring range

10°/23°/36°

8°/16°/31°

5°/11°/21°

4°/8°/15°

Elec. permiss. shaft speed

 2600 rpm

 2000 rpm

 1200 rpm

 950 rpm

Protection EN 60529

Complete, mounted encoder: IP00

Mass

 0.6 g/1 g/1.7 g

1)Accuracy of graduation
2)

Baseline error

 ±0.8”/10°

Position error per signal
period3)±0.06”±0.04”±0.025”±0.02”

Position noise RMS(1 MHz)0.006”

0.004”

0.003”

0.002”

376 832 000

491 520 000

819 200 000

1 032 192 000

Measuring step

0.0034”0.0026”0.0016”0.0013”

Reference marksOne

Hub inside diameter (D1)

13 mm

32 mm

62 mm

104 mmHub outside diameter (D2)

57 mm

75 mm

109 mm

151 mmMech. permissible speed

 2600 rpm

 2000 rpm

 1200 rpm

 950 rpm

Elec. permiss. shaft speed

 2600 rpm

 2000 rpm

 1200 rpm

 950 rpm

Moment of inertia

1.6 · 10

5.7 · 10–5 kgm2

3.1 · 10–4 kgm2

1.1 · 10–3 kgm2

Protection EN 60529

Complete, mounted encoder: IP00

Mass

 57 g 185 g 289 g4)

Positions/revolution
4)

4)5)

–5

kgm2

 92 g1)1)2)* Please select when ordering
1)
With serial interface
2)
With TTL serial interface and depending on the selected interpolation* Please select when ordering
1)
When centered with two scanning heads
2)
For mechanical centering as per the mounting instructions
3)
	The position error per signal period and the accuracy of the graduation together yield the encoder-specific error; for additional errors
arising from installation and the bearing of the measured shaft, see Measurement accuracy
4)With serial interface
5)
With TTL serial interface and depending on the selected interpolation

30

31

ERO 2000 series• High resolution and accuracy• Low mass and low mass moment of inertia• Consisting of an AK scanning head and TKN circular scale• TKN segment versions with position detection via homing track

Graduation carrier ¬ 18.6 mm(segment version: 18.6 mm × 9 mm)
AK ERO 20x0

TKN ERO 2000
2:1

TKN ERO 2002
2:1

3h6
 18.6

2.6

Incremental tracks: 230.750.01

12.7

Graduation carrier ¬ 30 mm

30.750.01

9.7

2.7

6.8

Incremental tracks: 1

3h6



X

0.003

(12.7)

 30

18.6

.7



 5.2)

 3.7



X
8:1


 13.2)

 5 H6



42
17.




 1.5H7



A-A

0.35

2:1

3x M2
 0.1



20

 

1.3±0.2

6.8

2x M2
 0.1

0.005 A

B

X

(0.5)

(10.15)

ISO 4762 - M2 - 8.8

B C LEB D LE

2.6

0.05 / 12.7
0.1 / 26

26

A

12.7

3.35 ±0.2

ISO 4762 - M2 - 8.8
ISO 7092 - 2

20.8

Required mating dimensions

0.1 B

A



21.14



X

5:1



 5.2

 3H7
(or 3.1±0.05)

D 13.2

18.54





6.4

2:1

2.6





0.02 B
0.01 B



B



22.5°

22.5°

120°



HOMING
HIGH level

14.4

6.4

9

C

14.4

26

17

9




5

(0.55)

0.1 / 26 AA

LOW level

A

7°5°


18.54

ISO 4762 - M3 - 8.8
ISO 7092 - 3





2:1

A

1
2
3
4
5
6
7

= Bearing= Reference mark= Positive direction of rotation= Centering collar= Marks for circular scale centering (3x120°)= Fine adjustment of the scanning head for obtaining optimal incremental signals= Alternative cable outlet and connector are available= Optical center point= For centering of circular scale with two scanning heads

LE = Line element (ISO 1101: 2008)

28.8

B
h
R
1
2
3
4
5
6

32

26.1

5.9

93.3°

= Bearing of mating shaft= Signal edge of the homing track= Position of the reference mark
= Direction of shaft rotation for ascending position values= Fine adjustment of the scanning head for optimal incremental signals= Cylindrical pin for positioning and Moiré adjustment (must be removed after positioning)= Dimension for alignment of the circular scale via the centering pin of the circular scale= Dimension for mounting the circular scale via optical alignment;
do not use the outer glass edge of the circular scale= Optional: mounting with two scanning heads

34

33

Specifications

TKN ERO 20021) (segment)

Scanning head

AK ERO 2080

Circular scale

TKN ERO 2000 (full circle)

Interface» 1 VPP

Measuring standard

SUPRADUR graduation on glass

Reference mark signal

Square-wave pulse

Measuring range360°

 1 MHz

Signal periods

4096

2500

2500 over 360°15-pin D-sub connector (male) with 0.5 m/1 m/1.5 m/3 m cable12-pin SHR-12V-S connector (female) with 0.5 m/1 m/1.5 m/3 m cable
Cable outlet on the left or right and straight or angled

Accuracy of graduation

±8”

±10“

–

Baseline error

 ±2”/10°

Cable lengthWith HEIDENHAIN cable:  20 m; during signal adjustment with the PWM 21:  3 m

±0.3”

±0.5”

±0.5”

Supply voltage

DC 5 V ±0.5 V

Position error per signal
4)
periodCurrent consumption

 150 mA (without load)

RMS position noise(1 MHz)

0.03”

0.04”

0.04”

Vibration 55 Hz to 2000 Hz
Shock 6 ms

2
 500 m/s (EN 60068-2-6)
2
 1000 m/s (EN 60068-2-27)

Reference marks

One

Operating temperature–10 °C to 70 °C

Inside diameter of hub

5 mm

–

–

Protection

IP50

Dimensions of graduation
carrier

 30 mm

 18.6 mm

18.6 mm x 9 mm

Centering pin

–

3 mm

3 mm

Cutoff frequency

1)

–3 dB

Electrical connection*

Mass		
						Scanning head
ConnectorCable 5 g (without cable)
 75 g 22 g/m* Please select when ordering
1)
Maximum frequency during referencing: 500 kHz

2)

3)

45°

One

Mech. permissible shaft speed  14 000 rpm
–7

kgm2

–

One on every side 24 000 rpm
2.2 · 10–8 kgm2

Moment of inertia

4.1 · 10

Protection EN 60529

Complete, mounted encoder: IP00

Mass

 5.2 g 0.56 g

1.1 · 10–8 kgm2

 0.36 g

1)

	Along with their incremental graduation, the TKN ERO 2002 segment versions feature a homing track for position detection (see h inmating dimensions). The signal for position detection from the scanning head is transmitted in the TTL level via a separate line and istherefore directly available. The incremental signals correspond to the VPP interface.
2)
When centered with two scanning heads
3)
For mechanical centering as per the mounting instructions
4)	The position error per signal period and the accuracy of the graduation together yield the encoder-specific error; for additional errors
arising from installation and the bearing of the measured shaft, see Measurement accuracy

34

35

HEIDENHAIN encoders with » 1 VPP
interface provide highly interpolable voltage
signals.

			

position values

The EnDat interface is a digital bidirectional
interface for encoders. It is capable ofoutputting position values, reading andupdating information stored in the encoder,and storing new information in the encoder.
Thanks to the serial transmission method,
only four signal lines are required. The
data (DATA) are transmitted in synchronism
with the CLOCK signal from the downstream
electronics. The type of transmission(position values, parameters, diagnostics,etc.) is selected via mode commands sent
to the encoder by the downstream
electronics. Some functions are available
only with EnDat 2.2 mode commands.

Signal period
360° elec.

The sinusoidal incremental signals A and
B are phase-shifted by 90° elec. and have atypical amplitude of 1 VPP. The illustrated
sequence of output signals—with B
lagging A—applies to the direction of
motion shown in the dimension drawing.
The reference mark signal R has a uniqueassignment to the incremental signals. The
output signal may be lower next to thereference mark.

Ordering designation

Command set

Incremental signals

EnDat01

EnDat 2.1 or EnDat 2.2

With

EnDat21

Without

EnDat02

EnDat 2.2

With

EnDat22

EnDat 2.2

Without

Versions of the EnDat interface

Absolute encoder

Alternative
signal shape(rated value)

Downstream electronics
Incremental
signals *)A, B, R measured with oscilloscope in differential mode
Absolute
position value

Further information:
For detailed descriptions of all available
interfaces, as well as general electricalinformation, please refer to the Interfacesof HEIDENHAIN Encoders brochure.

Operatingparameters

Operatingstatus» 1 VPP A*)
EnDat interface

Interfaces» 1 VPP incremental signals

Parameters of the encoder
Parameters manufacturer forof the OEM
EnDat 2.1
EnDat 2.2

» 1 VPP B*)*) Depends on thedeviceIncremental signals « TTL
HEIDENHAIN encoders with the « TTL
interface incorporate electronics that
digitize sinusoidal scanning signals with orwithout interpolation.
The incremental signals are transmitted
as the square-wave pulse trains Ua1 and Ua2,phase-shifted by 90° elec. The referencemark signal consists of one or morereference pulses Ua0, which are gated with
the incremental signals. In addition, theintegrated electronics produce theirinverted signals ¢, £, and ¤ fornoise-proof transmission. The illustrated
sequence of output signals—with Ua2
lagging Ua1—applies to the direction of
motion shown in the dimension drawing.
The fault detection signal ¥ indicatesfault conditions such as an interruption in
the supply lines, failure of the light source,etc.
The distance between two successive
edges of the incremental signals Ua1 andUa2 through 1-fold, 2-fold, or 4-foldevaluation is one measuring step.

36

Fault

Signal period 360° elec.

Measuring step after
4-fold evaluation

The inverted signals ¢, £, and ¤ are not shown

Further information:
For detailed descriptions of all available
interfaces, as well as general electricalinformation, please refer to the Interfacesof HEIDENHAIN Encoders brochure.

Further information:
For detailed descriptions of all available
interfaces, as well as general electricalinformation, please refer to the Interfacesof HEIDENHAIN Encoders brochure.

37Pin layout

ERP 880

ERP 1000

12-pin M23 coupling

15-pinD-sub connector(male)

12-pin SHR-12V-S connector (female)

1 2 3 4 5 6 7 8 9 10 11 12

12-pin PCB connector
on ERP 880

Power supply

Power supply

Incremental signals

12

2

10

11

5

6

8

1

3

4

9

7

/

2a

2b

1a

1b

6b

6a

5b

5a

4b

4a

3b

3a

/

UP

SensorUP

0V

Sensor
0V

A+

A–

B+

B–

R+

R–

VacantBrown/
GreenBlue

White/
Green

White

Brown

Green

Gray

Pink

Red

Black

/

Cable shield connected to housing; UP = Power supply voltage
Sensor: The sense line is connected in the encoder with the corresponding power line.
Vacant pins or wires must not be used!

38

Other signals

Vacant Vacant
VioletYellow

EnDat

Incremental signals

Serial data transmission/other signals

4

12

2

10

1

9

3

11

14

7

13

15

5

6

8

1

–

2

–

3

4

6

5

8

7

9

11

12

10

/

UP

SensorUP

0V

Sensor
0V

/

/

/

/

/

/

Ua1

Ua1

Ua2

Ua2

Ua0

Ua0

UaS Vacant

A+

A–

B+

B–

R+

R–

VaVa- Vacant Vacant Vacantcant1) cant1)

Gray

Pink

Red

Black

Violet Yellow

TTL» 1 VPP
Brown/
Green/White/
Green/

Brown GreenDATA CLOCK DATA Vacant CLOCK
VaVaVacant1) cant1) cant1)

/

/

/

Shield lies on housing; UP = Power supply voltage
Sensor: The sense line is connected in the connector with the corresponding power line.
Vacant wires and pins must not be used.
1)
Required for signal adjustment with the PWM 21

39

Testing equipment and diagnostics

ERO 2000
15-pin D-sub connector (male)

HEIDENHAIN encoders provide all of theinformation needed for commissioning,monitoring, and diagnostics. The type of
information available depends on whether
the encoder is incremental or absolute andon which interface is being used.

12-pin SHR-12V-S connector (female)

1 2 3 4 5 6 7 8 9 10 11 12Power supply» 1 VPP

Incremental signals

Other signals

4

12

2

10

1

9

3

11

14

7

13

8

6

15

1

–

2

–

3

4

6

5

8

7

9

12

10

11

UP

SensorUP

0V

Sensor
0V

A+

A–

B+

B–

R+

R–

Vacant1)

H/

Vacant1)

Brown/
Green/White/
Green

/

Brown

Green

Gray

Pink

Red

Black

VioletShield on housing; UP = Power supply voltage
Sensor: The sense line is connected in the connector with the corresponding power line.
Vacant pins or wires must not be used.
1)
Required for signal adjustment with the PWM 21

Green/ Yellow/ Yellow
Black Black

Incremental encoders mainly have 1 VPP,
TTL, or HTL interfaces. TTL and HTL
encoders monitor their signal amplitudes
internally and generate a simple fault
detection signal. With 1 VPP signals, ananalysis of the output signals is possible
only with external testing devices or
through the use of computation resourcesin the downstream electronics (analog
diagnostic interface).
Absolute encoders use serial datatransmission. Depending on the interface,
additional 1 VPP incremental signals can be
output. The signals are extensively monitored
within the encoder. The monitoring results(particularly valuation numbers) can betransmitted to the downstream electronics
along with the position values via the serialinterface (digital diagnostic interface). The
following information is available:• Error message: position value is notreliable• Warning: an internal functional limit of
the encoder has been reached• Valuation numbers:– Detailed information about theencoder’s function reserve– Identical scaling for all HEIDENHAIN
encoders– Cyclic reading capability
This enables the downstream electronics toevaluate the current status of the encoderwith little effort, even in closed-loop mode.
For the analysis of these encoders,
HEIDENHAIN offers the appropriate PWM
inspection devices and PWT testing
devices. Based on how these devices areintegrated, a distinction is made between
two types of diagnostics:• Encoder diagnostics: the encoder isconnected directly to the testing or
inspection device, thereby enabling adetailed analysis of encoder functions.
• Diagnostics in the control loop: the PWM
testing unit is linked into the closed
control loop (e.g., via a suitable testing
adapter). This enables real-time diagnosisof the machine or system during operation.
The available functions depend on theinterface.

40

Diagnostics with the PWM 21 and ATS software

Initial setup with the PWM 21 and ATS software

41

PWT 101
The PWT 101 is a testing device for thefunctional testing and adjustment of
incremental and absolute HEIDENHAIN
encoders. Thanks to its compact andrugged design, the PWT 101 is ideal for
portable use.

PWT 101
Encoder input
only for HEIDENHAIN
encoders• EnDat• Fanuc Serial Interface• Mitsubishi high speed interface• Panasonic Serial Interface• Yaskawa Serial Interface• 1 VPP• 11 µAPP• TTL

Display

4.3-inch color flat-panel display (touchscreen)

Supply voltage

DC 24 VPower consumption: max. 15 W

Operating temperature

0 °C to 40 °C

Protection EN 60529

IP20

Dimensions

 145 mm × 85 mm × 35 mm

PWM 21The PWM 21 phase-angle measuring unit,
in conjunction with the included ATS
adjusting and testing software, serves as
an adjusting and testing package for the
diagnosis and adjustment of HEIDENHAIN
encoders.

PWM 21
Encoder input• EnDat 2.1, EnDat 2.2, or EnDat 3 (absolute value withor without incremental signals)• DRIVE-CLiQ• Fanuc Serial Interface• Mitsubishi high speed interface• Yaskawa Serial Interface• Panasonic serial interface• SSI• 1 VPP/TTL/11 µAPP
• HTL (via signal adapter)

InterfaceUSB 2.0

Supply voltage

AC 100 V to 240 V or DC 24 V

Dimensions

258 mm × 154 mm × 55 mm
ATSLanguages

German or English (selectable)

Functions• Position display• Connection dialog• Diagnostics• Mounting wizard for the EBI/ECI/EQI, ERP 1000,
ERO 2000, and others• Additional functions (if supported by the encoder)• Memory contents

System requirements
and recommendations

PC (dual-core processor > 2 GHz)
RAM > 2 GB
Operating systems: Windows 7, 8, and 10 (32-bit / 64-bit)
500 MB of free hard drive space

Further information:
For a detailed description, refer to the
PWT 101 Product Information document.
Further information:
For detailed descriptions, refer to thePWM 21/ATS Software Product
Information document.

DRIVE-CLiQ is a registered trademark of Siemens Aktiengesellschaft.

42

43

Mastering nanometer accuracy

DR. JOHANNES HEIDENHAIN GmbH
Dr.-Johannes-Heidenhain-Straße 583301 Traunreut, Germany +49 8669 31-0
 +49 8669 32-5061
info@heidenhain.dewww.heidenhain.com
1401414-20 · 1 · 03/2023 · CD · Printed in Germany

HEIDENHAIN
worldwide