140-002D

Check tool table size

Press MOD key, select 'SYSTEM FILES', navigate to TNC:\table\TOOL.T and check the number of tool entries. Compare against your control's specifications (typically 254-32767 depending on model).

Use PGM MGT file manager to view TOOL.T properties - file size and number of lines indicate total tool entries.

Audit and consolidate tools

Review TOOL.T for duplicate entries, obsolete tools, or placeholder entries. Delete unused tools using the table editor or export, clean, and re-import the file.

Always backup TOOL.T to USB before editing. Document which tools are removed to avoid program errors referencing deleted tool numbers.

Verify tool call methodology

Check if NC programs use TOOL CALL with proper tool number references. Ensure programs aren't inadvertently creating tool entries through automatic tool measurement cycles.

Use 'Test Run' mode with tool table display active to observe which tools are being called during program execution.

Inspect point table entries

Navigate to TNC:\table\ and open active .PNT files. Check total number of point definitions. TNC controls typically support 10,000+ points but specific configurations may have lower limits.

Sort point table by date to identify if recent probing cycles are rapidly accumulating points without clearing old data.

Review pallet table configuration

If using pallet management, check PAL files for excessive pallet definitions. Access via MOD > PALLET TABLE and verify the number of active pallets matches your physical setup.

Modifying pallet tables while jobs are queued can cause production errors. Coordinate with operators before changes.

Clear historical measurement data

If using automated probing cycles (Cycle 3, Cycle 4, or TT 130), old measurement results may accumulate. Archive and delete outdated .PNT files or implement programmed clearing using FN18: SYSWRITE ID990 NR6.

Create a housekeeping subroutine that runs weekly to archive point tables older than 30 days to external storage.

Identify the active NC block

Note the block number where alarm occurred. Open the NC program and locate the corresponding line. Look for FN18, FN26, or loop structures using QL parameters as array indices.

Use Program Run > Single Block mode to step through suspect areas while monitoring Q-parameter display (MOD > Q-PARAMETER LIST).

Verify array indexing logic

Check FOR loops or REPEAT structures that increment Q-parameters used as array indices. Ensure loop counters don't exceed table dimensions. Common error: reading tool table with index > actual tool count.

Q-parameter ranges vary by control model. TNC 320 supports Q0-Q1399, while TNC 640 supports Q0-Q1999 plus QS parameters.

Test with boundary protection

Add conditional checks before table read operations: IF +QL[index] LT [max_table_size] / FN26: TABREAD / ENDIF. This prevents read attempts beyond table limits.

Use FN18: SYSREAD ID51 NR1 to read current tool table size, then compare index values against this dynamic limit rather than hardcoded values.

Review SYSREAD/TABREAD syntax

Verify FN18/FN26 commands use correct ID numbers and NR parameters per Heidenhain documentation. Incorrect ID/NR combinations can cause unexpected data writes to wrong memory locations.

Cross-reference ID numbers with your specific control software version - SYSREAD ID assignments changed between NC Software versions 340.49x and 606.xxx series.