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3. SIGNALS AND WIRING
3.5 Alarm Occurrence Timing Chart
CAUTION
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When an alarm has occurred, remove its cause, make sure that the operation
signal is not being input, ensure safety, and reset the alarm before restarting
operation.
When an alarm occurs in the servo amplifier, the base circuit is shut off and the servo motor is coated to a
stop. Switch off the main circuit power supply in the external sequence. To reset the alarm, switch the
control circuit power supply off, then on.
However, the alarm cannot be reset unless its cause of occurrence is removed.
ON
OFF
power supply
ON
OFF
Base circuit
Dynamic brake
Valid
Invalid
ON
OFF
Servo on
(SON)
ON
OFF
Reset
(RES)
ON
OFF
Ready
(RD)
ON
OFF
Trouble
(ALM)
1s
Alarm occurs.
Remove cause of trouble.
Brake operation
Brake operation
Power off
Power on
Instantaneous power fallure alarm
50ms or
more
15ms or more
Precautions for alarm occurrence
1) Overcurrent, overload 1 or overload 2
If operation is repeated by switching control circuit power off, then on to reset the overcurrent (A.
32), overload 1 (A. 50) or overload 2 (A. 51) alarm after its occurrence, without removing its cause,
the servo amplifier and servo motor may become faulty due to temperature rise. Securely remove
the cause of the alarm and also allow about 15 minutes for cooling before resuming operation.
2) Instantaneous power failure
If a power failure continues 15ms or longer, the undervoltage (A. 10) alarm will occur. If the
power failure still persists for 20ms or longer, the control circuit is switched off. When the power
failure is reset in this state, the alarm is reset and the servo motor will start suddenly if the
servo-on signal (SON) is on. To prevent hazard, make up a sequence which will switch off the
servo-on signal (SON) if an alarm occurs.
3) Position control mode
When an alarm occurs, the home position is lost. When resuming operation after deactivating the
alarm, make a return to home position.
