1A0-01A9

Access Machine Parameters

Press MOD key, enter password if required, then select 'Machine Parameters' from the MOD menu. Navigate to the axis-specific parameters for the axis shown in the alarm (typically C-axis for rotary tables).

Use the search function in machine parameters (if available on your TNC version) by pressing the 'Search' softkey and entering the MP number directly.

Verify Modulo Configuration

Locate MP1710 for the affected axis. If a value exists (typically 360.0000 for degrees), the axis is configured as modulo. Note this value or take a screenshot for documentation.

MP1710 defines the modulo range—360.0 for degrees, 400.0 for gon, or 6.2832 for radians (2π). Verify this matches your rotary axis encoder configuration.

Disable Software Limit Switches

Locate MP1620 (negative software limit) and MP1630 (positive software limit) for the same axis. Delete the values or comment them out by placing a semicolon (;) at the beginning of each line. Both parameters must be inactive for modulo axes.

Disabling software limits removes position boundary protection. Ensure hardware limit switches (MP1510/MP1520) are properly configured and functional.

Save and Reboot Control

Save the machine parameter changes using the 'Save' or 'End' softkey. Perform a complete control reboot (power cycle recommended) to ensure all axis configuration parameters are reloaded and validated.

After reboot, manually jog the modulo axis through several complete rotations to verify proper wraparound behavior at the modulo boundary.

Review Axis Configuration History

Determine if the axis was recently changed from linear to modulo configuration. Check documentation, service logs, or consult with machine tool builder about the intended axis configuration.

Compare current machine parameters with the machine tool builder's original parameter set if available—often stored in TNC:\system\machineparams.bak or similar backup file.

Check All Related Axis Parameters

In addition to MP1620/MP1630, verify MP1000 (axis designation), MP1010 (axis name), MP1410 (reference point), and MP1420 (reference marking) are consistent with modulo operation. Linear-specific settings may cause conflicts.

For modulo axes, MP1410 (reference point position) is often set to 0.0, and MP1420 should match the encoder's distance-coded reference marking configuration.

Clear Software Limit Parameters

Set MP1620 and MP1630 to inactive by deleting values or commenting out. Verify no conditional or axis-exchange parameters are inadvertently activating software limits through alternate parameter sets.

Some machines use MP1635 for software limit monitoring mode—verify this is also compatible with modulo operation or set to appropriate value per machine documentation.

Validate Hardware Limit Protection

Since software limits are being removed, confirm hardware limit switches are properly configured in MP1510 (negative hardware limit) and MP1520 (positive hardware limit) and are physically functional on the machine.

Test hardware limits by carefully jogging near the physical limits while monitoring PLC inputs in the MOD diagnostics screen (TNC:\plc\plcdiag.htm on newer controls).

Perform Reference Point Cycle

After parameter changes and reboot, execute a reference point cycle for the modulo axis. This validates the complete axis configuration and establishes the modulo zero position correctly.

Monitor the axis position display during referencing—modulo axes should show positions within their modulo range (0-360°) after successful referencing.