230-04B7

Access Machine Parameter Tables

Press MOD key, enter machine parameter password, navigate to General > Machine Parameters to access MP tables.

Ensure machine is in a safe state and motion is disabled before modifying machine parameters.

Verify MP100 Axis Assignment

Check MP100 (Axis Assignment) for the affected axis. Verify bit coding is correct: Bit 0-2 define axis type (0=linear, 1=rotary modulo, 2=rotary shortest path, etc.). Ensure the value matches your machine's actual axis configuration.

MP100 uses bit-coded values - use the TNC help function (HELP key) while in the parameter field to see the bit definitions.

Check MP101 Axis Names

Review MP101 (Axis Names) to ensure each axis has a unique, valid name (X, Y, Z, A, B, C, U, V, W). Check that no duplicate axis names exist and that special characters are not present.

Axis names must follow Heidenhain conventions - use only standard axis letters, and ensure rotary axes are properly designated as A, B, or C.

Verify Channel Assignment

Cross-reference MP100 and MP101 with the physical axis channel connections. Ensure the logical axis configuration matches the actual CNC channel and drive topology.

Document the original settings before making changes - use MOD > Data Transfer to save a backup of machine parameters.

Identify Encoder Parameters for Affected Axis

Navigate to the encoder-specific MP range: MP600-699 for encoder 1 (typically X), MP700-799 for encoder 2 (Y), etc. Note the current encoder type setting in MP6x0 (x=encoder number).

The encoder number typically corresponds to axis number, but verify in your machine documentation as this varies by machine manufacturer.

Verify Encoder Type MP6x0/7x0/8x0

Check MP600/700/800 (Encoder Type) matches actual hardware: 0=no encoder, 1=1 Vpp sin/cos, 2=EnDat01, 3=EnDat02, 4=SSI, 11=TTL. Confirm the value corresponds to the actual encoder interface installed on the axis.

Setting an incorrect encoder type can cause communication errors and may prevent the control from starting.

Check Encoder Line Count and Reference Marks

Verify MP6x1 (Signal Period) matches encoder datasheet specifications. For EnDat encoders, check MP6x2 (Reference Mark Type): 0=none, 1=one ref mark, 2=distance-coded. Ensure settings match encoder capabilities.

EnDat encoders transmit their line count to the control - if MP6x1 doesn't match what the encoder reports, this alarm can occur.

Review Encoder Monitoring Parameters

Check encoder monitoring settings in MP640-660 range (tolerance bands, monitoring windows). Ensure these are enabled and set appropriately for your encoder type. Missing or zero values in required monitoring parameters can trigger configuration errors.

For absolute encoders, ensure the position validity check parameters are properly configured - the control expects these to be defined.

Access Axis-Specific Parameter Range

Navigate to the affected axis parameter block: MP1000-1999 for X-axis, MP2000-2999 for Y-axis, MP3000-3999 for Z-axis, etc. Focus on the 130x, 140x, and 150x parameter families.

Use the search function in the MP table (Enter search term) to quickly find specific parameters like 'software limit' or 'reference point'.