SRVO-248: Deadman switch status abnormal
The deadman's two redundant inputs disagree - a chain fault specific to the deadman switch.
What it means
The deadman's two redundant inputs disagree - a chain fault specific to the deadman switch. The manual gives a beautiful field test: release both deadman switches at once and watch for SRVO-236. If it appears, the switch was just half-pressed; no hardware problem.
Common causes
Ranked by what technicians most often find, most likely first.
- Deadman pressed halfway - the everyday cause.
- Hardware, in FANUC's order: teach pendant, pendant-to-E-stop-board cable, E-stop board, E-stop-board-to-main-board cable.
How to fix it
- Release both deadman switches simultaneously. If SRVO-236 'Chain failure is repaired' appears, there is no hardware fault. Press RESET and carry on.
- If SRVO-236 does not appear, swap hardware in order with the controller de-energized and locked out for each exchange: pendant, pendant cable, E-stop board, then board-to-main cable.
- After any repair, run the chain release: press and release an E-stop button on the pendant or operator panel, press F4 'RES_1CH' on the Alarm ACTIVE screen [4 Alarm / ACTIVE], then press RESET.