SRVO-138: SDAL alarm (pulse coder signal error)
Software caught a signal error from the encoder - and the manual offers a genuinely useful diagnostic split: if a power cycle restores normal operation, it was noise; if not, the encoder is dead.
What it means
Software caught a signal error from the encoder - and the manual offers a genuinely useful diagnostic split: if a power cycle restores normal operation, it was noise; if not, the encoder is dead.
Common causes
Ranked by what technicians most often find, most likely first.
- Electrical noise on the encoder line (recoverable by power cycle - improve shielding).
- Failure or disconnection inside the encoder (not recoverable - replace).
How to fix it
- Cycle power. If operation resumes normally, treat it as noise: enhance the encoder cable shielding so it doesn't recur.
- If the alarm survives the power cycle, the encoder is defective: replace the motor and perform mastering.
Quick facts
- Category
- Servo
- Affected series
- R-30iB; R-30iB Mate; R-30iB Plus; R-30iB Mate Plus
- Alarm family
- SRVO
Related codes
- SRVO-136DCLVAL alarm (aux amplifier DC link low)
- SRVO-135FSAL alarm (aux amplifier fan stopped)
- SRVO-134DCLVAL / DCLVAL (PS) alarm (DC link voltage low)
- SRVO-133FSAL (PS) alarm (power supply fan stopped)
- SRVO-131LVAL / LVAL (PS) alarm (PS control voltage low)
- SRVO-130OHAL1 (PS) alarm (power supply overheat)
- SRVO-126Quick stop error
- SRVO-124Check HardStop if Hit