
B-63945EN/02 9.DIGITAL SERVO
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Action 2: Alarms that may be caused by noise
If an alarm is issued intermittently or an alarm is issued after the
emergency stop state is canceled, the cause of the alarm is
probably noise. In this case, provide sufficient noise protection.
If an alarm is issued even after noise protection is provided,
replace the detector.
9.3.5 Alarms Related to Serial Communication
An alarm is identified from the data of alarm 4 and alarm 8.
Alarm 4 Alarm 8
DTE CRC STB PRM DTE CRC STB SPD
Description
1
1
1
Serial Pulsecoder communication alarm
1
1
1
Separate serial Pulsecoder communication alarm
Action:
An error occurred in serial communication. Check if the cable is
connected correctly and also check if the cable is not
disconnected and broken. If a CRC or STB error occurs, the
cause may be noise. In this case, provide noise protection. If an
alarm is always issued after the power is turned on, the
Pulsecoder, amplifier control board (i series), or separate detector
interface unit (i series) may be faulty.
9.3.6 Alarms Related to Disconnection
An alarm is identified from the data of alarms 1, 2, and 6.
Alarm 1 Alarm 2 6
OVL LVA OVC HCA HVA DCA FBA ALD EXP SFA
Description Action
1 1 1 0
Hard disconnection
(separate A/B phase
disconnection)
1
1 0 0 0
Soft disconnection (closed
loop)
2
1 0 0 1
Soft disconnection (α
Pulsecoder)
3
Action 1:
This alarm is issued when a separate A/B phase scale is used.
Check if the A/B phase detector is connected correctly.
Action 2:
This alarm is issued when the position feedback pulse change is
smaller than the velocity feedback pulse change. This means that
this alarm is not issued in a semi-closed loop. Check if the