SRVO-062

Verify battery voltage before replacement

Navigate to MENU → SYSTEM → Variables, then type $MCR.$GENOVERRIDE to view system variables. Check $SCR.$BATNO1 through $BATNO6 (for 6-axis robot) to identify which axis triggered the alarm. Battery voltage should be >3.0V (nominal 3.6V). Zero or near-zero voltage confirms battery failure.

Document all axis battery voltages before replacement. If multiple axes show low voltage (<3.2V), replace all batteries during this maintenance window to avoid repeat service calls.

Replace pulse coder battery pack

Power down controller completely. Open robot base battery box (location varies by model: M-10/20 under J1 cover, R-2000 at base rear panel). Replace battery pack (typical P/N: A98L-0031-0025 or A06B-6114-K504) ensuring correct polarity. Verify connector is fully seated and cable routing matches original configuration.

Do NOT hot-swap the pulse coder battery while robot is powered on. This can cause encoder damage or EEPROM corruption requiring board replacement.

Perform PULSE RESET procedure

Power up controller. Navigate to MENU → SYSTEM → Master/Cal. Press F3 [RES_PCA]. Screen displays 'Reset pulse coder alarm for ALL axes?'. Press F4 [YES], then press RESET key on teach pendant. Alarm should clear but SRVO-068 MAST alarm will appear indicating mastering required.

Alternative method: MENU → SYSTEM → Variables, set $MCR.$SPC_RESET=1, then press RESET. This method allows selective axis reset if needed by setting individual $MCR_GRP[1].$SPC_RESET[axis] variables.

Re-master robot using Quick Master or fixture

With SRVO-068 active, navigate to MENU → SYSTEM → Master/Cal. If Quick Master capable (R-30iB with zero-point mastering): select axis, press F3 [MASTER], move to mechanical zero notch, press F5 [DONE]. Otherwise use mastering fixture: jog robot to fixture position, enter mastering values from fixture plate, press F4 [SET] for each axis.

Mastering must be performed in T1 mode with deadman switch engaged. Improper mastering can cause crashes, damage tooling, or create unsafe robot motion.

Verify mastering accuracy

After mastering all axes, move robot to known reference positions or teach points. Check position accuracy within ±0.5mm for typical applications. Navigate to MENU → SYSTEM → Variables and verify $DMR.$MASTER_DONE[1-6]=TRUE for all axes. Run a test program with low override (25%) to confirm motion path accuracy before full production.

Record new mastering data: MENU → SYSTEM → Master/Cal, note all mastering counts and save to USB via MENU → FILE → Backup. Store this data with robot documentation for future reference.

Identify affected axis from alarm detail

Press ALARM on teach pendant, note which axis number appears in SRVO-062 alarm detail (e.g., 'BZAL alarm(G:1 A:3)' indicates Group 1, Axis 3). Navigate to MENU → ALARM → F1 [ALARM LOG] to check if alarm occurred on multiple axes simultaneously, indicating possible main cable issue versus single-axis battery connector problem.

If BZAL appears on all axes simultaneously after a normal shutdown, suspect main battery box connector or internal arm cable harness rather than individual battery failure.

Inspect battery box connections

Power down completely and lockout/tagout. Open robot base battery box. Inspect battery holder connector (typically white 6-pin or 8-pin Molex). Check for: loose connector not fully seated, corroded pins, damaged cable insulation near connector. Disconnect and reconnect firmly while checking for bent pins. Measure continuity from battery terminals through cable to connector.

Ensure robot is powered off and locked out before opening any covers. Battery voltage is low (3.6V) but short circuits can damage encoder boards.

Check internal arm cable routing and condition

For persistent disconnection issues, inspect cable routing through robot arm (requires mechanical disassembly). Common failure points: J2/J3 elbow flex area, cable carriers, pass-through grommets. Look for pinched cables, worn insulation, or cables binding against mechanical stops. Check for proper cable dress per Fanuc maintenance manual for specific robot model.

Before full disassembly, verify cable continuity: disconnect battery box connector, use multimeter to check continuity from battery box pins to encoder connector at each joint. Resistance should be <1 ohm per conductor.

Reconnect and perform PULSE RESET

After reconnecting or repairing cable, power up controller. Follow PULSE RESET procedure: MENU → SYSTEM → Master/Cal → F3 [RES_PCA] → F4 [YES] → RESET. If alarm does not clear, check $MCR.$PWDIS_PCA system variable = 0 (if set to 1, pulse coder alarm reset is disabled and requires parameter change).

Set system variable $SCR.$BCKUPALM = 1 (if available on your controller version) to enable early warning when battery voltage drops, providing more notice before BZAL occurs.

Complete re-mastering procedure

Execute mastering as detailed in Cause Block 1, Step 4-5. After mastering, cycle robot through full range of motion for all axes at 50% override to verify no cable binding or intermittent connections. Monitor for alarm recurrence over 100+ cycles.

After cable repair, enable mastering logging: set parameter 19600 (Master/Cal log enable) to 1. This logs all mastering events to help diagnose if position is lost again due to intermittent cable issues.