SRVO-033

Check for preceding BZAL alarms

Press MENU > ALARM > F2 [ALARM LOG]. Look for BZAL-001 (Battery Low Voltage Alarm) or BZAL-002 (Battery Disconnected) entries that preceded the SRVO-033. Note which axis number is referenced in the BZAL alarm.

BZAL alarms typically appear 7-14 days before complete battery failure. If you see recent BZAL alarms, replace batteries immediately after mastering to prevent recurrence.

Measure pulse coder battery voltage

Access MENU > SYSTEM > Variables. Toggle to $MISC and find $MCR.$BTSCNT[axis] for battery status counters. Values below 3.0V indicate replacement needed. Alternatively, use a multimeter to measure battery voltage directly at the servo amplifier or motor battery connector (should be 3.6V nominal for lithium batteries).

Never disconnect pulse coder batteries with robot power on. This will immediately cause mastering data loss.

Replace defective batteries

With robot power OFF and locked out, replace pulse coder batteries on affected axes. For R-30iA/B systems, typical battery is A98L-0031-0025 or A06B-6114-K504 depending on amplifier series. After replacement, batteries need 30 minutes to charge before powering on.

Replace all axis batteries at once if robot is over 5 years old. Battery life is typically 5-7 years, and if one fails, others are likely near end-of-life.

Perform complete robot mastering

After battery replacement, perform mastering procedure: MENU > SYSTEM > Master/Cal > [axis selection] > F1 [DETAIL]. Use Quick Master if mastering fixture available, or Single Count Master method if robot is at known zero position. Record all mastering count values in $DMR.$MCR_GRP[1].$MASTER_CNT[axis] after completion.

Robot must be moved to proper zero position for each axis before executing mastering command. Incorrect mastering will cause positional errors and potential crashes.

Backup mastering data and verify

After successful mastering, immediately backup: MENU > FILE > F2[BACKUP]. Select 'Pulse Coder' or 'All of Above' to save mastering data to UT1/UT2 or external device. Verify by jogging to known taught positions and checking position accuracy. Update $MASTER_ENB to value 1 for all axes in Master/Cal screen.

Save a text file copy of all $DMR.$MCR_GRP[1].$MASTER_CNT values. If mastering is lost again, these values can be manually re-entered to avoid full re-mastering procedure.

Verify which axis encoder was replaced

Check maintenance logs or alarm history (MENU > ALARM > F2[ALARM LOG]) to identify which axis had hardware replacement. Compare serial numbers on encoder label with maintenance records. The SRVO-033 alarm detail should indicate specific axis numbers affected.

On R-30iB systems, check system variable $DMR.$ENC_SRL[axis] to view encoder serial numbers currently detected by controller.

Verify encoder connection and operation

Navigate to MENU > SYSTEM > Variables > $CRNT_ANG to verify the new encoder is transmitting position data. Values should change smoothly when axis is jogged manually (power off, brakes released). If values are frozen or erratic, check encoder cable connections at amplifier and motor.

Ensure encoder cable routing matches original installation. Kinked or stressed encoder cables will cause position feedback errors and potential servo alarms.

Position robot at mastering reference

Using mastering fixture or reference marks on robot, manually position the affected axis to its zero-degree reference position. For robots without fixtures, use mechanical alignment marks typically found on J1 base, J2/J3 arm sections. Verify position using dial indicator or laser alignment tool for critical axes.

J4, J5, J6 wrist axes often have alignment pins or reference holes that accept mastering pins for precise positioning. Check robot mechanical unit maintenance manual for exact locations.

Execute single-axis mastering

With axis at zero position: MENU > SYSTEM > Master/Cal > Select axis > F1[DETAIL] > F3[ZERO]. Confirm the axis number, then press F4[EXEC]. Controller will capture current encoder pulse count as new zero reference and write to $DMR.$MCR_GRP[1].$MASTER_CNT[axis]. Verify $MASTER_ENB shows '1' for axis.

Do not execute mastering with axis positioned incorrectly. This will shift the zero reference and cause all taught positions to be offset, potentially causing robot crashes.

Test accuracy and update programs

Jog robot to multiple known taught positions and verify accuracy within ±0.5mm for typical applications. Check $MASTER_CARE variable to confirm mastering care counter reset. If significant positional offset exists, re-teach critical positions or perform payload calibration. Backup all mastering data immediately after verification.

After encoder replacement on J2 or J3, perform Payload Identification (MENU > SETUP > Payload) to re-calibrate dynamic model. Encoder timing changes can affect torque compensation.