231-92E0

Access Machine Parameters

Press MOD key, select 'Machine Parameters', navigate to cfgServoMotor section for the affected axis.

Always backup parameters before making changes using the parameter export function.

Check motStr Value

Verify the motStr parameter value matches encoder specifications. For EnDat 2.2 without line count info, set motStr = 1.

Incorrect motStr values can cause servo instability and positioning errors.

Apply and Test

Save parameter changes, perform control restart, and verify encoder initialization in the PLC status display.

Monitor the EnDat diagnostic data during startup to confirm proper encoder communication.

Access Motor Table

Navigate to Setup menu, select 'Motor Parameters', locate the motor table for the affected servo axis.

Cross-reference motor model number with Heidenhain motor database for correct STR values.

Verify STR Entry

Check STR value against motor nameplate or encoder specifications. Common values are 1, 2048, 4096, or specific line counts.

Wrong STR values will cause scaling errors and potential axis runaway conditions.

Update Motor Configuration

Correct the STR entry, save motor table, and restart the control to reinitialize encoder parameters.

Use Heidenhain's motor selection tool to verify correct parameter combinations.

Check EnDat Status

Access PLC status, navigate to encoder diagnostics, verify EnDat communication status and error counters for the affected axis.

Look for CRC errors or timeout messages in the EnDat diagnostic display.

Inspect Cable Connections

Verify encoder cable connections at motor and drive ends, check for proper shielding and cable routing away from power cables.

Always power down the system before checking encoder cable connections.

Test Encoder Function

Use the encoder test function in service menu to verify proper EnDat communication and data integrity.

Compare signal quality readings with baseline values from commissioning documentation.

Identify Encoder Change

Compare current encoder part number with parameter backup or commissioning documentation to identify specification changes.

Check encoder manufacturing date codes to confirm recent replacement.

Update All Related Parameters

Modify cfgServoMotor motStr, motor table STR, and any scaling parameters to match new encoder specifications.

Ensure all parameter changes are consistent across motor, encoder, and scaling configurations.

Perform Reference Run

Execute reference point approach and verify proper axis scaling and positioning accuracy with new encoder parameters.

Document all parameter changes for future reference and maintenance records.