1238

Common Causes

• ZA and ZB were commanded closer than the new LT control parameter 1 distance
• ZB approached too far while XA and XB were not both at the Plus variable limit, violating parameter 2 logic
• Z moved too close under spindlehead interlock while X was not at Plus variable limit, violating parameter 3 logic
• Interference-distance parameter set incorrectly for the actual machine layout, or an operation/program move entered the protected zone

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code 1 = ZA/ZB separation became smaller than the new LT control parameter 1 distance.; code 2 = ZB entered the parameter 2 forbidden distance while XA and XB were not both at Plus variable limit.; code 3 = Under spindlehead interlock, Z entered the parameter 3 forbidden distance while X was not at Plus variable limit.
2. 2Read the code first: code 1 is ZA/ZB too close, code 2 is ZB approach with XA and XB not together at Plus variable limit, and code 3 is Z approach with X not at Plus variable limit under spindlehead interlock.
3. 3For code 1, jog ZA or ZB apart to restore a distance greater than the parameter 1 setting, then identify the program block or manual move that drove the two Z axes together.
4. 4For code 2, confirm XA and XB are both positioned at the Plus variable limit before allowing ZB to advance; if they were, have a qualified person verify the parameter 2 distance matches the machine's actual interference geometry.
5. 5For code 3, move X to the Plus variable limit required by the spindlehead interlock before moving Z, then check whether the parameter 3 distance is plausible for the spindlehead clearance.
6. 6If the positions look physically safe, do not change values casually; have the parameter 1/2/3 interference settings checked against the machine configuration, then correct the operation or program path that entered the zone.