Product Information

ECN 425
EQN 437
Absolute Rotary Encoders
with Tapered Shaft andExpanding Ring Couplingfor Safety-RelatedApplications
ID 1178028-02
ID 1178029-02

06/2022

ECN 425, EQN 437
Rotary encoders for absolute position feedback with safe singleturn information• 65 mm installation diameter• 07B expanding ring coupling• 65B tapered shaft• IP64 protection

Required mating dimensions

A = Bearing of mating shaft
M1 = Measuring point for operating temperature
M2 = Measuring point for vibration; see D741714
1 = Clamping screw for coupling ring, width A/F 2; tightening torque: 1.25 Nm –0.2 Nm
2 = Screw plug, width A/F 3 and 4; tightening torque: 5 Nm +0.5 Nm
3 = Screw: DIN 6912 – M5x50 – 08.8 – MKL; width A/F 4; tightening torque: 5 Nm +0.5 Nm
4 = M10 back-off thread
5 = Compensation of mounting tolerances and thermal expansion; no dynamic motion permitted
6 = Chamfer at start of thread is obligatory for material bonding anti-rotation lock
7 = Direction of shaft rotation for ascending position values

2Product Information ECN 425/EQN 437   06/2022

Specifications

ECN 425 singleturn

Functional safetyfor applications with up toAs a single-encoder system for monitoring and control-loop functions:• SIL 2 as per EN 61508 (further basis for testing: IEC 61800-5-3)• Category 3, PL d, according to EN ISO 13849-1:2015
Safe in the singleturn rangePFH1)

 10 · 10–9 (probability of dangerous failure per hour)

Safe position2)

Encoder: ±1.76° (safety-related measuring step: SM = 0.7°)
Mechanical coupling: ±2° (exclusion for loosening of shaft and stator coupling,
designed for accelerations of  300 m/s2)

Interface/ordering designation

EnDat 2.2/EnDat22

Position values per revolution

33 554 432 (25 bits)

Revolutions–Calculation time tcal/clock frequency

 7 µs/ 16 MHz

System accuracy at 20 °C±20”Supply voltage

DC 3.6 V to 14 V

Power consumption (maximum)

At 3.6 V:
At 14 V:

Current consumption (typical)

At 5 V: 80 mA (without load)

Electrical connection

Cable (1 m) with 8-pin M12 coupling (male)

Cable length3)

 100 m (at clock frequency ≤ 8 MHz) 20 m (at clock frequency ≤ 16 MHz)

Shaft

65B tapered shaft ( 9.25 mm); taper 1:10

Permissible shaft speed 15 000 rpm

Starting torque at 20 °C (typical)

 0.01 Nm

Moment of inertia of rotor

 2.6 · 10–6 kgm2

Angular acceleration of rotor 1 · 105 rad/s2

Natural frequency fN (typical)≥ 1800 Hz

Permiss. axial motion of measured shaft

 ±0.5 mm

Vibration 55 Hz to 2000 Hz4)
Shock 6 ms2
 300 m/s (EN 60068-2-6)
 2000 m/s2 (EN 60068-2-27)

Operating temperature5)

Stationary cable: –40 °C to 100 °C; Moving cable: –10 °C to 100 °C

Trigger threshold for exceeded
temperature error message6)

125 °C (measuring accuracy of the internal temperature sensor: ±1 K)

Relative humidity

 93% (40 °C/21 d as per EN 60068-2-78), condensation excluded

Protection rating EN 60529

IP67 on housing; IP64 at shaft inlet(read about insulation under Electrical safety in the Interfaces of HEIDENHAIN Encoders
brochure; contamination from the ingress of fluids must be avoided)Mass 0.3 kg

ID number1178028-021)

4096 (12 bits)

 600 mW
 700 mW	For use at ≤ 2000 m above sea level(≤ 6000 m above sea level upon request)2)	Further tolerances may arise in the downstream electronics
after position value comparison (contact manufacturer)3)	See the EnDat description in the Interfaces of HEIDENHAIN
Encoders brochure)
Product Information ECN 425/EQN 437   06/2022

EQN 437 multiturnAt 3.6 V:
At 14 V:

 700 mW
 800 mW

At 5 V: 95 mA (without load) 12 000 rpm

1178029-024)

10 Hz to 55 Hz, 4.9 mm constant peak to peak	For information on operating temperature, shaft speed, andsupply voltage, see General mechanical information in theRotary Encoders brochure6)	The internal temperature evaluation is not designed withfunctional safety5)

3

MountingElectrical connection

The tapered shaft of the rotary encoder ispressed onto the measured shaft andfastened with a central screw. It isparticularly important to ensure that thepositive-locking element of the stator
coupling securely engages thecorresponding slot in the measured shaft.
Use a central screw with material-bondinganti-rotation lock (see Mounting
accessories). The stator coupling isclamped by means of an axially tightenable
screw in a locating hole.

Pin layout8-pin M12 couplingPower supply

More information:
For the customer-side mounting
design, the material specifications forsteel apply to the customer-side shaft.
For the customer-side stator, thematerial specifications for aluminumapply.

Serial data transmission

82513476UP

Sensor UP0VSensor 0 V

DATA

DATA

CLOCK

CLOCK

Brown/GreenBlue

White/GreenWhite

Gray

Pink

VioletYellow

Cable shield connected to housing; UP = Power supply voltage
Sensor: The sense line is connected in the encoder with the corresponding power supply line.
Vacant pins or wires must not be used!
Note for safety-related applications: Only completely assembled HEIDENHAIN cables are qualified. Do not modify cables or exchange
their connectors without first consulting with HEIDENHAIN Traunreut!

Also comply with the other material
properties in the Encoders for Servo
Drives brochure (ID 208922-xx).

Mounting accessories
ScrewsScrews (central screw, mounting screws) are not included in delivery and can be orderedseparately.
ECN 425, EQN 437 screws1)
Central screw
for fastening the shaft1)

DIN 6912 – M5×50 – 08.8 – MKL ID 202264-54

Quantity
10 or 100

With coating for material bonding anti-rotation lock

For more mounting information and mounting aids, see the mounting instructions
and the Encoders for Servo Drives brochure. The mounting quality can be inspectedwith the PWM 21 and ATS software.

DR. JOHANNES HEIDENHAIN GmbH
Dr.-Johannes-Heidenhain-Str. 583301 Traunreut, Germany +49 8669 31-0
 +49 8669 32-5061
info@heidenhain.dewww.heidenhain.com

4

Product Information ECN 425/EQN 437   06/2022

1378400 · 00 · A · 02 · 06/2022 · PDF

This Product Information document supersedes all previous editions, which thereby
become invalid. The basis for ordering from HEIDENHAIN is always the Product
Information document edition valid when the order is placed.

More information:
Comply with the requirements described in the following documents to ensure correctand intended operation:• Operating Instructions				
1379276-xx