130-07D6

Identify Affected Drive Location

Note the '%1' parameter from the alarm display indicating which axis or spindle drive is not responding. Locate the corresponding inverter module in the cabinet and identify its X1xx connector position.

The alarm typically shows the axis name (e.g., X, Y, Z, S) or spindle designation - cross-reference this with your electrical documentation to find the physical inverter location.

Inspect Drive Bus Connections

Power down the machine completely. Check the X1xx connector at both the CC control unit and the affected inverter module. Verify locking clips are engaged, no bent pins exist, and the connector housing shows no damage or contamination.

Disconnect main power and wait 5 minutes for DC bus capacitors to discharge before touching any inverter connections.

Check Cable Shield and Routing

Verify the drive bus cable shield is properly terminated at both ends using the shield clamps. Ensure the cable is routed away from power cables and has not been damaged by cabinet door movement or sharp edges.

Drive bus cables should maintain minimum 200mm separation from motor power cables and use dedicated cable trays where possible.

Perform Cable Swap Test

If you have multiple identical drives, temporarily swap the drive bus cable with a known-working adjacent drive module to determine if the fault follows the cable or remains with the drive hardware.

This test quickly isolates cable vs. drive module faults - if the alarm moves to the other axis, the cable is defective.

Check Drive Module LED Indicators

Examine the LED status indicators on the front of the affected inverter module. Refer to the drive module's documentation for LED fault codes. No LEDs or solid red typically indicates processor or power supply failure within the drive.

Most Heidenhain-compatible inverters have multi-color LEDs that show: green=OK, flashing yellow=warning, red=fault. Document the exact LED pattern for support calls.

Verify Drive Module DC Bus Voltage

Using a multimeter, measure the DC bus voltage at the inverter module terminals (typically 560-680VDC for 400V systems). Low or absent DC bus voltage prevents the drive processor from powering up and communicating.

Use CAT III rated test equipment and appropriate PPE. DC bus voltages exceed 600VDC and are lethal.

Isolate Drive from System

Disconnect the motor cable and encoder cable from the drive module. Power up the system and check if the drive now shows ready status (communication restored). If yes, the fault is motor/encoder related, not drive communication.

A short circuit in the motor or encoder can cause the drive to enter hardware protection and stop responding to communication.

Access Drive Parameters Directly

Navigate to MOD > Machine Parameters > Axis/Spindle Configuration and attempt to read the drive parameters for the affected axis. If parameters cannot be read, the drive communication is definitively broken.

Compare readable parameters from working drives vs. the failed drive to confirm communication path integrity.

Review Drive Address Settings

Access MOD > Machine Parameters > Axis/Spindle Configuration and verify the configured drive bus address for the affected axis matches the hardware address set on the physical inverter module (typically via DIP switches or rotary switch).

Drive addresses must be unique and sequential. Common addressing starts at 0 or 1 depending on the inverter manufacturer.

Perform Drive Bus Scan

Navigate to MOD > Test Functions > Digital Drive Test (exact menu path varies by TNC model). Execute a bus scan function to detect all drives present on the communication bus and compare to expected configuration.

The bus scan will show which physical addresses respond - missing addresses indicate hardware or cabling faults, unexpected addresses indicate configuration errors.

Verify Axis Assignment Parameters

Check machine parameter MP100 (axis assignment) and the corresponding drive parameters (MP1xxx series for each axis). Ensure the logical axis name matches the configured drive module address and type.

After any machine parameter changes, a full control restart is required - not just NC reset.