SRVO-063: RCAL alarm (rotation counter abnormal)
The encoder's built-in rotation counter miscounted - the pulse coder's own bookkeeping is suspect.
What it means
The encoder's built-in rotation counter miscounted - the pulse coder's own bookkeeping is suspect. Frequently a grounding/noise story rather than a dead encoder, and sometimes not a real alarm at all: if it appears with SRVO-068/069/070, chase those instead.
Common causes
Ranked by what technicians most often find, most likely first.
- Poor controller or motor grounding letting electrical noise corrupt the counter.
- Genuine pulse coder failure.
- Phantom occurrence alongside SRVO-068 DTERR / 069 CRCERR / 070 STBERR - the communication alarms are the real story.
How to fix it
- Check SRVO-068, SRVO-069, and SRVO-070 in the alarm history first. If any are present, work those remedies.
- With the controller de-energized and locked out, verify the earth cable between the controller and the robot is secure at the grounding plate, and reinforce motor-flange grounding on auxiliary axes.
- If grounding is sound and the alarm recurs on its own, replace the motor with the robot de-energized, locked out, and the gravity-loaded axis blocked or supported so it cannot drop when the motor is removed.
- After the motor is refitted and power is restored, perform a pulse reset and power cycle, then master the axis in T1 low speed with the deadman held and the cell clear.