NORD Drivesystems BU0510 - Manual (Page 73)

7 Troubleshooting
BU 0510 GB-3911 Subject to technical alterations 73
7.2.3 Sources of error with incremental position detection (without absolute encoders)
Symptom Additional test Possible cause
Position drifts away 
Interference pulse in the encoder cable
No reproducible precision when
approaching the position, even at low speeds
(n < 1000 1/min))

Interference pulse in the encoder cable
only at high speed
(n > 1000 1/min)

Pulse number in combination with the encoder
cable length / Cable type too large (Pulse
frequency too large)

Loose encoder / Installation fault
7.2.4 Sources of faults for position detection with absolute encoders
Symptom Additional test Possible cause
Actual position value always runs
to the same value and then no
longer changes 
Encoder connection faulty
Position not always found at the
same place, axis sometimes jumps
backwards and forwards. Mechanical unevenness?

Axis stiff, axis jams etc.

Loose encoder / Installation fault
if the position value does not match
the encoder rotation or jumps Check absolute encoder
(remove, set parameter
speed and reduction ratio to
1, rotate encoder manually:
the displayed position must
match the rotations of the
encoder)

Encoder defective