230-02BF

Check Physical Connections

Inspect the handwheel cable connections at both the TNC control unit and handwheel. Ensure the connector is fully seated and locked.

Power down the machine before disconnecting/reconnecting handwheel cables.

Test Cable Continuity

Use a multimeter to check continuity on all pins of the handwheel cable. Check for shorts between conductors and to ground.

Heidenhain HR cables use specific pin assignments - refer to the handwheel manual for proper pinout.

Verify Cable Routing

Ensure the handwheel cable is not damaged by machine movement, pinched, or routed near high EMI sources like servo drives or spindle motors.

Access Handwheel Configuration

Navigate to MOD function, select Machine Parameters, then System/CfgHandwheel/type to view current handwheel configuration.

Write down current settings before making changes for easy rollback if needed.

Verify Handwheel Model

Check the physical handwheel label for exact model number (HR410, HR420, HR520, HR550, etc.) and compare with parameter setting.

Incorrect handwheel type can cause permanent damage to the handwheel electronics.

Update Configuration

Set System/CfgHandwheel/type parameter to match the actual handwheel model. Save parameters and perform a control restart.

Some handwheels require additional parameters like transmission rate and protocol version to be configured.

Test with Known Good Handwheel

If available, substitute with a working handwheel of the same model to isolate whether the issue is with the handwheel unit or system.

Ensure the substitute handwheel is configured for the same transmission protocol and baud rate.

Check Handwheel Power Supply

Verify the handwheel is receiving proper supply voltage (typically 5V or 12V depending on model) at the connector pins.

Use appropriate measurement techniques to avoid damaging sensitive electronics.

Inspect Handwheel Display

Check if the handwheel display is functioning. A blank or corrupted display often indicates internal electronics failure requiring handwheel replacement.

Check Interface Card Seating

Power down and inspect the handwheel interface card (if modular) for proper seating in the TNC backplane. Reseat if necessary.

Follow proper ESD procedures when handling TNC interface cards.

Test Interface Voltages

Measure supply voltages at the handwheel connector on the TNC side. Verify 5V, 12V, and ground references are within specification.

Voltage measurements should be taken with handwheel disconnected to avoid loading effects.

Verify Interface Card Status

Check TNC diagnostics for handwheel interface card status and any related hardware fault indicators in the system status displays.