5222

Access SYSTEM > ALARM to record the exact alarm occurrence time and frequency. Check alarm history (ALARM LOG screen) to determine if 5222 is recurring or a single isolated event.

Navigate to SYSTEM > DIAGNOSIS and check diagnostic number 800-803 for memory error counters if available on your control series. Note any incrementing error counts indicating ongoing memory issues.

Power cycle the control completely (turn off main power, wait 30 seconds, power on) and observe if the alarm recurs within 24 hours of normal operation. Single occurrences may be transient; multiple occurrences within days indicate hardware replacement needed.

Ensure all programs and parameters are backed up before power cycling. Loss of absolute position data may occur on some systems.

If alarm recurs, replace the FROM/SRAM board (A20B-8200-0540 or equivalent for your series) or main CPU board containing the SRAM module. Verify part number compatibility with your control model and software version before ordering.

Replacing SRAM board requires battery backup maintenance and parameter/program restoration from backup. System may require re-initialization and reference position return after board replacement.

Check control cabinet temperature using diagnostic screen SYSTEM > DIAGNOSIS > #300 (internal temperature monitor if equipped). Verify cabinet cooling fans are operational and air filters are clean. Target internal temperature should remain below 55°C (131°F).

Inspect all grounding connections on the control chassis, verify main ground impedance is less than 0.1 ohms to facility ground. Check for loose ground straps on cabinet doors and control mounting bolts.

Review installation for proper cable routing: ensure signal cables (encoder, serial communication) are separated from power cables by minimum 300mm. Verify ferrite cores are installed on encoder feedback cables and serial communication lines.

If high-power equipment (welders, large motors) shares the facility electrical system, install isolation transformers or line filters on the CNC power supply. Monitor for alarm correlation with specific machine operations or external equipment activation.

Check battery voltage at SYSTEM > DIAGNOSIS > #300-301 (battery voltage display). Verify voltage is above 3.0VDC for lithium batteries. If below 2.8VDC, battery replacement is urgent regardless of alarm.

Low battery alarm (BAT or 5000-series alarms) should appear before SRAM errors, but not always. Battery failure can cause parameter loss.

Inspect battery pack connector on main board for corrosion, loose pins, or physical damage. Clean contacts with electronic contact cleaner if oxidation is present. Verify battery holder is secure and not cracked.

Replace battery assembly with OEM Fanuc battery (A98L-0031-0025 or equivalent for your control series). Follow proper battery replacement procedure: keep main power ON during replacement to prevent parameter loss.

Never remove battery with main power OFF unless parameters are backed up. Battery replacement must be completed within 5 minutes to prevent memory loss.