5 Troubleshooting
 
5
- 34 -
During Startup Fault Symptom Cause Conrming Methods
Input position 
reference.
Servo motor does 
not rotate.
Input reference pulse 
counter (H0B-13) is 0.
High/low-speed pulse input terminal is wired 
incorrectly.
When H05-00 = 0 (pulse is main position 
reference source), check whether high/low-
speed pulse input terminal is wired correctly 
by referring to Chapter 3 in the IS650P User 
Manual. Meanwhile, check whether the 
setting of H05-01(reference pulse selection) is 
matched.
Position reference is not input.
1. Check whether FunIN.13: INHIBIT (pulse 
input forbidden) or FunIN.37: PulseInhibit (pulse 
forbidden) is used.
2. When H05-00 = 0 (pulse is main position 
reference source), host computer or other 
pulse generator does not output pulses. Check 
whether there are pulses into high/low-speed 
pulse input terminal. Please refer to the IS650P 
User Manual.
3. When H05-00 = 1 (step reference is main 
position reference source), check whether H05-
05 (step amount) is 0. If not, check whether 
FunIN.20: PosStep (DI position step reference) 
has been allocated and whether logic of 
corresponding terminal is valid.
When H05-00 = 2 (multi-position reference is 
main position reference source), check whether 
parameters in group H11 are set correctly. 
If yes, , check whether FunIN.28: PosInSen 
(internal multi-position enable) has been 
allocated and whether logic of corresponding 
terminal is valid.
5. If position change on y is used, check 
whether H05-29 (position change on y unlock) 
is set to 1(enabled). If yes, check whether 
FunIN.29: XintFree (position change on y 
unlocked) is used.
Servo motor rotates 
in reverse direction.
Input reference pulse 
counter (H0B-13) is 
negative.
When H05-00 = 0 (pulse is main position 
reference source), check whether the setting 
of H05-15 (reference pulse form) is consistent 
with actual pulse input. If not, it indicates that 
H05-15 is set incorrectly or terminal wiring is 
incorrect.
When H05-00 = 1 (step reference is main 
position reference source), check whether H05-
05 (step amount) is positive or negative. 
When H05-00 = 2 (multi-position reference is 
main position reference source), check whether 
each displacement is positive or negative.
When H05-00 = 2 (multi-position reference is 
main position reference source), check whether 
each displacement is positive or negative.
Check whether H02-02 (rotation direction 
selection) is set correctly.
Servo motor can rotate after preceding fault is removed.