YASKAWA SGD7S series Product Manual page 175

Problem Possible Cause
The encoder was subjected
Absolute to excessive vibration or
shock.
Encoder
Position
Deviation
Error (The
position
A failure occurred in the
that was
encoder.
saved in the
A failure occurred in the SER-
host con-
VOPACK.
troller when
the power
was turned
OFF is dif-
ferent from
the posi-
tion when
Host Controller Multiturn
the power
Data or Absolute Encoder
was next
Position Data Reading Error
turned ON.)
The P-OT/N-OT (Forward
Drive Prohibit or Reverse
Drive Prohibit) signal was
input.
Overtravel
Occurred
The P-OT/N-OT (Forward
Drive Prohibit or Reverse
Drive Prohibit) signal mal-
functioned.
4.2 SERVOPACKs with MECHATROLINK-III Communications References
4.2.7 Troubleshooting Based on the Operation and Conditions of the Servomotor
Confirmation
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.
Check the external power
supply (+24 V) voltage for
the input signals.
Check the operating con-
dition of the overtravel
limit switches.
Check the wiring of the
overtravel limit switches.
Check the settings of the
overtravel input signal
allocations (Pn50A/
Pn50B).
Check for fluctuation in
the external power supply
(+24 V) voltage for the
input signals.
Check to see if the opera-
tion of the overtravel limit
switches is unstable.
Check the wiring of the
overtravel limit switches
(e.g., check for cable
damage and loose
screws).
Continued from previous page.
Correction Reference
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.
Correct the external
power supply (+24 V)
–
voltage for the input
signals.
Make sure that the
overtravel limit switches
–
operate correctly.
Correct the wiring of
*
the overtravel limit
switches.
Set the parameters to
*
correct values.
Eliminate fluctuation
from the external power
–
supply (+24 V) voltage
for the input signals.
Stabilize the operating
condition of the over-
–
travel limit switches.
Correct the wiring of
the overtravel limit
–
switches.
Continued on next page.
4
4-107