YASKAWA SGD7S series Product Manual page 119

Problem Possible Cause
There is a SERVOPACK
pulse counting error due to
noise.
Absolute
Encoder
The encoder was subjected
Position
to excessive vibration or
Deviation
shock.
Error (The
position
that was
saved in the
host con-
A failure occurred in the
troller when
encoder.
the power
A failure occurred in the SER-
was turned
VOPACK.
OFF is dif-
ferent from
the posi-
tion when
the power
was next
Host Controller Multiturn
turned ON.)
Data or Absolute Encoder
Position Data Reading Error
4.1 SERVOPACKs with Analog Voltage/Pulse Train References
4.1.7 Troubleshooting Based on the Operation and Conditions of the Servomotor
Confirmation
Check to see if there is
noise interference on the
I/O signal line from the
encoder or Serial Con-
verter Unit.
Check to see if vibration
from the machine
occurred.
Check the Servomotor
installation (mounting sur-
face precision, securing
state, and alignment).
Check the linear encoder
installation (mounting sur-
face precision and secur-
ing method).
–
–
Check the error detec-
tion section of the host
controller.
Check to see if the host
controller is executing
data parity checks.
Check for noise interfer-
ence in the cable
between the SERVO-
PACK and the host con-
troller.
Continued from previous page.
Correction Reference
Implement counter-
measures against noise
for the encoder or
–
Serial Converter Unit
wiring.
Reduce machine vibra-
tion. Improve the
mounting state of the
–
Servomotor or linear
encoder.
Replace the Servomo-
–
tor or linear encoder.
Replace the SERVO-
–
PACK.
Correct the error detec-
tion section of the host
–
controller.
Perform parity checks
for the multiturn data or
–
absolute encoder posi-
tion data.
Implement counter-
measures against noise
and then perform parity
checks again for the
–
multiturn data or abso-
lute encoder position
data.
Continued on next page.
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