[Cause]
A mismatch between STO-OUT and STO-FB was detected in the additional axis servo power-off (local stop) function. The value displayed in the message is the local stop number where the alarm occurred. The value is displayed in hexadecimal (base 16), and each bit corresponds to an item number on the DCS local stop screen (1:No.1, 2:No.2, 4:No.3: 8:No.4, 10:No.5, 20:No.6, 40:No.7, 80:No.8).
[Countermeasure]
1. Check the setting of DCS partial stop screen.
2. Check whether the system variable ($LS_IOPORT[n].$MO_GRP_NUM) setting and the servo amplifier (iSV) switch setting (SW1) are correct. For details, refer to ‘R-30iB STO Specification Additional Axis Servo OFF (Local Stop) Function Maintenance Preparation Material’ (A-95028). (This alarm is issued when the system variable ($LS_IOPORT[n].$MO_GRP_NUM) has been set, but the servo amplifier (iSV) switch setting (SW1) is set to not used.)
3. Please replace the cable connection between the emergency stop board and the servo amplifier (iSV).
4. Please replace the cable connection between the emergency stop board and the servo amplifier (iSV).
5. Replace the emergency stop board.
6. Replace the servo amplifier (iSV).
Note To clear this alarm, power needs to be cycled.