Speed Deviation Monitoring - Mitsubishi Electric MELSEC Q Series Programming Manual

2 SAFETY OBSERVATION FUNCTION

2.4.9 Speed deviation monitoring

Safety observation error
(SM57)
Shut-off signal
(Y A)
Both Motion CPU and PLC CPU monitor if the difference between the feedback
(Note-1)
speed and command speed
allowance value of speed deviation during speed monitoring.
If the difference continues to exceed the allowance value over "speed monitoring error
detection time", "Safety observation error (error code: 113)" occurs and the shut-off
signal is turned OFF.
Set the allowance value of speed deviation and speed monitoring error detection time
by parameters.
(Note-1): Value calculated from the time derivative of command position from servo amplifier to Motion CPU.
(Note-2): Value calculated from the time derivative of command position from servo amplifier to Motion CPU.
V
Allowance value of
speed deviation
(Parameter)
Command speed
0
(Note-2)
of Motion CPU does not exceed the
Speed monitoring error detection time
(Parameter)
Feedback speed
2 - 15
Error occurs
t