
B-63494EN/02 8.MAINTENANCE
- 145 -
No. Meaning Description Servo axis
operation when
alarm is issued
487 ILLEGAL SAFETY MODE
(CNC)
The CNC detected that safety signal mode D (state in
which the guard is open although no guard open request
is input) was set, or the guard is open when guard unlock
signal (*LGD) is not output.
Check if the guard state signal(SGD) is correctly
connected.
If an alarm is issued in safety mode C (state in which a
guard open request is input and the guard is open), guard
unlocking is disabled. Accordingly, this alarm may be
issued.
Immediate stop
488 SAFE TEST OVER TIME A MCC off Test was not completed within the set time
(parameter No. 1946).
Check the MCC contact.
Immediate stop
489 SAFETY PARAM ERROR
(CNC)
The CNC detected a safety parameter error.
Set the safety parameters again.
Relative parameters are as follows.
No.1023, No.1829, No.1838, No.1904, No.1942, No.1943,
No.1944, No.1945, No.1946, No.1947, No.1948, No.1950,
No.1998, No.4372, No.4438, No.4440, No.4442,
No.13800, No.13802, No.13810, No.13821 to No.13824,
No.13831 to No.13838, No.13880 to No.13911, No.13920
to No.13951, No.13960 to No.13991
Immediate stop
490 CNC SAFETY FUNCTION
ERROR
An error occurred in safety functions of CNC:
1 CNC or monitor detected the inexecution of CNC
safety functions.
2 A mismatch between the CNC results of the safety
functions and the monitor or spindle results of them
occurred.
3 An error occurred in a CNC RAM test.
4 An error occurred in a CNC CPU test.
5 Test at power-up was not executed.
Replace the CPU card.
Immediate stop
491 LOCAL BUS TEST ERROR An error occurred in a local bus test. The mother board
may be faulty.
Replace the mother board.
Immediate stop
492 F-BUS TEST ERROR An error occurred in an F-BUS test. The mother board or
option board may be faulty.
The F-BUS test is carried out if a sub-CPU board or
loader board is used.
Immediate stop
493 SAFETY DO SIGNAL ERROR
(CNC)
The CNC detected that a mismatch between a safety
position switch signal or programmable safe-related
output signal output via the PMC and the same signal
output via the FSSB has lasted for the period of time set
in parameter No. 1945 or more.
Check the safety output signal.
Alternatively, when no FSSB I/O module (extension) is
used, a setting is made to use a safety position switch
output from the extension module. Use the FSSB I/O
module (extension) or set the corresponding parameter
(No. 13880 to No. 13911) to 0.
Immediate stop