Speed Monitoring Function Omitting External Auxiliary Pulse Input - Mitsubishi Electric MELSEC Q Series Programming Manual

2 SAFETY OBSERVATION FUNCTION

2.11 Speed Monitoring Function Omitting External Auxiliary Pulse Input

When not using external auxiliary pulse input, the safety performance level in a stopped state
during speed monitoring (command speed or motor feedback speed is 0) is PL d/category 2. If
stopping for a long period, stop with a mechanical lock such as a brake (SBC), or shut-off
operation (STO).
When not using external auxiliary pulse input, the longest time a motor stopped status
(command speed or motor feedback speed is 0) can be maintained is one hour. Without
external auxiliary pulse input, the encoder cannot diagnose small oscillation, and so after one
hour in the stopped status "Safety observation error (error code: 120)" occurs, and the shut-off
signal turns OFF.
Do not turn ON the small oscillation request signal when set to not use external auxiliary pulse
input. "Safety observation error (error code: 121)", or "Safety observation warning (error code:
203)" occurs, and small oscillation does not complete correctly.
Standstill monitoring (SOS) function cannot be used when set to not use external auxiliary
pulse input. At power supply ON "Safety observation error (error code: 27, detail code
H 61)" occurs, and shut-off signal does not turn ON.
The speed monitoring function conducts a double observation by monitoring the
command speed and motor feedback speed with two CPUs. In order to maintain safety
when stopped (command speed or motor feedback speed is 0), the motor rotation
pulse generated from an external sensor is input and checked for consistency with the
motor feedback position.
When speed monitoring parameter "External sensor input X device number" is set to
"1FFF", and "Number of pulses per external sensor rotation" and "Movement amount
per external sensor rotation" is set to "2147483647", this consistency check is disabled,
and speed monitoring can be conducted without external auxiliary pulse input.
CAUTION
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