
8.MAINTENANCE B-63494EN/02
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8.2.5 System Alarms
No. Meaning Description
900 ROM PARITY Parity error of the CNC, macro, or servo ROM.
When the dual check safety function is used:
1 Parity error of the CNC, macro, or servo ROM
2 CRC error of the CNC, servo, or monitor ROM
Reinstall the indicated ROM in flash memory.
920 SERVO ALARM (1-4
AXIS)
Servo alarm (first to fourth axis). A watchdog alarm condition occurred, or a RAM parity
error occurred in the axis control card.
In the dual check safety function with 4-axes control card, servo alarm (first/second axis,
or monitor).
Replace the axis control card.
921 SERVO ALARM (5-8
AXIS)
Servo alarm (fifth to eighth axis). A watchdog alarm condition occurred, or a RAM parity
error occurred in the axis control card.
In the dual check safety function with 6-axes control card, servo alarm (monitor).
In the dual check safety function with 8-axes control card, servo alarm (fifth/sixth axis, or
monitor).
If the 8-axes control card dedicated to dual check safety function (5DSP card) is used
with the dual check safety function, a servo alarm (fifth to eight axis) is issued.
Replace the axis control card.
973 NON MASK
INTERRUPT
An NMI of an unknown cause occurred.
If the 8-axes control card dedicated to dual check safety function (5DSP card) is used
with the dual check safety function, this alarm is issued, even when a servo alarm
(monitor) is issued.
8.2.6 Boot System Alarms
Message Description
ROM PARITY ERROR:
NC BASIC. HIT SELECT.
Parity error of the CNC basic ROM.
When the dual check safety function is used:
1. Parity error of the CNC basic ROM
2. CRC error of the CNC basic ROM
Reinstall the CNC basic ROM in flash memory.