Self-Diagnosis Function; Safety Signal Output Check Function - Mitsubishi Electric MELSEC Q Series Programming Manual

2 SAFETY OBSERVATION FUNCTION

2.10 Self-diagnosis Function

2.10.1 Safety signal output check function

Power supply
User safety sequence program
(Motion CPU side)
Transfer and check of the sequence
programs for safety observation
(Motion CPU to PLC CPU)
Safety signal output off check
(Motion CPU side)
Safety signal output off check
(PLC CPU side)
Output off check incomplete
(SM27)
Safety signal comparison
Shut-off signal
(Y A)
All output signals are turned OFF instantaneously by this function if the output signal of the
safety signal module is turned ON by the user safety sequence program after the power ON
and before the shut-off signal is turned ON. Design the machine so that any dangerous status is
occurred even when all output signal when all outputs signal points are turned OFF
instantaneously.
The safety signal cannot be controlled correctly in case of the transistor malfunction of
the safety signal module. Ensure the safety by checking the output signal using the
output off check function at power ON and output off check function every 24 hours.
(1) Output off check function at power ON
Confirm that all output signals from the safety signal module are turned OFF
normally before turning ON the shut-off signal after the power ON. Execute the
output off check of PLC CPU side after the output off check of Motion CPU side
is completed.
If an error is detected during PLC CPU side output check, "Safety observation
error (error code: 48)" occurs, and "Safety observation error (error code: 49)"
occurs during the check of the Motion CPU side.
When the safety signal comparison starts after the check, the shut-off signal is
turned ON.
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CAUTION
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