504Fault · Encoder / feedbackUsually repairable
SIMODRIVE 611U 504: Measuring Circuit Error, Motor Measuring System
What 504 means
The signal from the motor encoder is too weak or faulty, or the cable-break monitor tripped.
Symptoms
Fault on enable or while running, often when the cable moves or the machine vibrates.
Is it repairable?
Yes: encoders, encoder cables and the drive's encoder input are all repairable.
Common causes
- Damaged or wrong encoder cable
- Poor shield connection
- Loose connector
- Failed encoder
- Faulty encoder input on the control module
Safe checks
- 1Check the encoder cable along its length and at both connectors
- 2Make sure the shield is clamped
- 3Swap in a known-good cable if you have one
Drives hold dangerous voltage after power-off. Checks should only be done by qualified personnel, with power isolated and the DC link discharged.
Reviewed by AutomIQ repair technicians. Code and name from the SIMODRIVE 611 universal Function Manual.
Related SIMODRIVE 611U faults
- 003NMI due to watchdog
- 006Checksum test error
- 020NMI due to cycle failure
- 028Actual current sensing during power-up
- 505Measuring circuit error, motor measuring system absolute track
- 507Synchronization error, rotor position