330-008B

Verify Safety Circuit State

With machine in emergency stop, access MOD 9 (Service Mode) and navigate to 'Drive Diagnostics' or 'CC Status Monitor'. Check the RDY signal status for the affected axis - it should show RDY=0 when E-stop is active. If it shows RDY=1, the safety relay is stuck.

Do not attempt to release emergency stop if RDY signal shows active during E-stop condition - this indicates a safety system failure.

Measure Relay Contact Continuity

Power down the complete control system and disconnect axis motor power cables. Remove the X112 connector from the affected CC module. Use a multimeter to check continuity across the safety relay output pins (typically pins 1-2 for K1 and 3-4 for K2 on X112). Stuck relays will show <1 ohm resistance when they should be open circuit.

If you hear the relay clicking during power-up but contacts remain closed, the relay coil works but contacts are welded - this confirms relay replacement is needed.

Ensure all power is isolated and capacitors discharged (wait 5 minutes) before touching any CC module connections.

Replace CC Inverter Module

If stuck relay is confirmed, the CC inverter module power card must be replaced. Document the axis assignment and all parameter settings from the System Parameters (MOD function, System Settings). Replace the complete CC module with a spare, ensuring correct axis assignment in CfgAxisEnable parameters.

After replacement, perform a full drive commissioning including encoder reference marks and axis testing before returning to production.

Inspect X112 Connector and Pinout

Power down and remove the X112 connector from the CC module showing the alarm. Visually inspect for bent pins, corrosion, or wire insulation damage. Verify wiring against the machine's electrical schematic - ensure enable signals (typically +24VDC on specific pins) are wired to correct terminals.

Ensure main power and 24VDC control power are both isolated before disconnecting X112.

Check Enable Signal Logic Levels

With X112 disconnected from CC module, measure voltage on the enable input pins from the machine side connector. During E-stop condition, these should show 0VDC. If +24VDC is present during E-stop, the safety relay circuit or PLC output is faulty. Trace the circuit back to the safety relay module.

Compare the enable signal behavior on the faulted axis to a working axis - both X112 connectors should show identical voltage patterns during E-stop and enable sequences.

Test with Disconnected Enable Inputs

Reconnect X112 to CC module but temporarily remove the enable signal wires from the machine side of X112 (leave only ground connected). Power up the TNC. The CC should initialize without RDY=1 active. If alarm clears, the fault is in the machine's safety wiring, not the CC module.

Axes will not enable with this test configuration - this is diagnostic only to isolate the fault location.

Repair or Replace Wiring

If external wiring fault is confirmed, repair the damaged cables or replace the complete X112 harness section. Ensure all safety relay contacts controlling the enable signals are functioning correctly per the machine electrical schematic.

After wiring repair, document the MOD diagnostic screens showing correct RDY signal behavior during E-stop, enable, and disable sequences for future reference.