320-0028

Access machine parameter menu

Press MOD key, select 'Machine parameters', navigate to MP7210 series parameters using search function.

Use Ctrl+F to quickly search for MP7210 in the parameter list

Verify MP7210.0 arithmetic error mode

Check MP7210.0 value is within valid range (0-3): 0=ignore, 1=stop PLC, 2=alarm, 3=emergency stop.

Never set to undefined values above 3 as this creates system instability

Validate operand-specific settings

Review MP7210.1 through MP7210.7 for each arithmetic operand type, ensure all values match documentation specifications.

Cross-reference with PLC program to ensure error handling matches actual arithmetic operations used

Reset and test configuration

Save parameters, perform controlled restart, monitor for alarm recurrence during PLC initialization.

Open PLC program editor

Access Programming mode, select PLC, open the active PLC program file (typically plc.pl or main.pl).

Use the program manager to identify which PLC program is currently active

Search for arithmetic error handling code

Use Find function to locate ARITH_ERR, ERROR_HANDLING, or similar directives that may override machine parameters.

Document all changes before modifying PLC code to enable rollback if needed

Verify directive syntax and values

Check that all arithmetic error handling directives use valid syntax and operand values according to TNC PLC programming manual.

Pay special attention to operand %1 referenced in the alarm - this indicates the first operand configuration is invalid

Test PLC compilation

Compile PLC program and monitor for compilation errors or warnings related to arithmetic error configuration.

Access file management

Enter Programming mode, select file manager, navigate to TNC:\system\ directory to locate configuration files.

Always create backup copies before modifying system files

Examine SYS.SYS file

Open SYS.SYS file in text editor, search for PLC_ARITH or similar entries related to arithmetic error configuration.

Look for unusual characters, truncated lines, or values outside expected ranges

Restore from backup or default

If corruption found, restore SYS.SYS from known good backup or regenerate using machine parameter export function.

Use the 'Export machine parameters' function to create a clean configuration file

Verify system restart

Perform controlled system restart and monitor initialization sequence for successful PLC configuration loading.

Check software version information

Press HELP key, select 'About' to display current TNC software version and build information.

Note both the main version and any service pack numbers for compatibility checking

Review version release notes

Consult TNC software release documentation for changes to MP7210 series parameters or PLC arithmetic error handling.

Some software updates require machine parameter reinitialization

Update parameter configuration

Modify MP7210 series parameters according to new software version requirements, following migration guidelines.

Contact Heidenhain support for specific migration procedures if documentation is unclear

Validate updated configuration

Test all PLC arithmetic operations to ensure error handling works correctly with updated configuration.