Yaskawa Sigma-5 User Manual: Design and Maintenance - Linear Motors MECHATROLINK-III Communications Reference - Manual (Page 296)

8.4 Troubleshooting Malfunction Based on Operation and Conditions of the Servomotor
8-35
8
Trou
blesh
ooting
Absolute Linear
Scale Position
Difference Error
(The position
saved in the host
controller when
the power was
turned OFF is
different from the
position when the
power was next
turned ON.)
Noise interference due to incorrect
cable specifications of linear scale
connection cables.
The linear scale connection cables
must be tinned annealed copper
shielded twisted-pair or screened
unshielded twisted-pair cable with a
core of 0.12 mm
2 min.
Use the specified linear scale con-
nection cables.
Noise interference due to length of
linear scale connection cables.
Check the length of the linear scale
connection cables.
The length of each cable must be
equal to or shorter than the maxi-
mum wiring length listed here.
• Connection cables for serial con-
verter unit: 20 m
• Connection cables for linear
scale: 15 m
• Connection cables for hall sensor:
15 m
Noise interference due to damaged
linear scale connection cables.
Check if the linear scale connection
cables are bent and the sheaths are
damaged.
Replace the linear scale connection
cables and correct the cable layout.
Excessive noise to the linear scale
connection cables.
Check if the linear scale connection
cables are bundled with a high-cur-
rent line or near a high-current line.
Correct the cable layout so that no
surge is applied.
FG potential varies because of
influence of machines such as weld-
ers at the servomotor.
Check if the machines are correctly
grounded.
Ground machines correctly, and
prevent diversion to the FG on the
linear scale side.
SERVOPACK pulse counting error
due to noise interference
Check if there is noise interference
on the I/O signal line from the serial
converter unit.
Take measures against noise in the
serial converter unit wiring.
Excessive vibration and shock to
the linear scale
Check if vibration from the machine
occurred or linear scale installation
is incorrect (mounting surface accu-
racy and fixing method).
Reduce vibration from the machine,
or secure the linear scale installa-
tion.
A linear scale fault occurred. − Replace the linear scale.
A SERVOPACK fault occurred.
(The pulse count does not change.)
− Replace the SERVOPACK.
Host controller serial data reading
error
Check the error detection section of
the host controller.
Correct the error detection section
of the host controller.
Check if the host controller is exe-
cuting data parity checks.
Execute a serial data parity check.
Check noise in the cable between
the SERVOPACK and the host con-
troller.
Take measures against noise, and
again execute a serial data parity
check.
(cont’d)
Problem Probable Cause Investigative Actions Corrective Actions