Code 280-0436: Q303 in meas. cycle undefined!
Issue Description & Safety Warning
The Heidenhain TNC Series CNC has triggered a critical Q303 in meas. cycle undefined! alarm. Immediate attention from a qualified operator or maintenance technician is required to prevent secondary damage to the equipment or spoiled parts during the manufacturing cycle. Always ensure standard safety and LOTO procedures are followed before accessing electrical cabinets.
Official Troubleshooting Steps
[Cause of error] In one of the measuring cycles 410 to 418, you did not define the parameter Q303 (measured value transfer)(current value = -1). For reasons of security, however, selection of the measured value transfer is required to write the results of measurement in a table (datum table or preset table). [Error correction] Change parameter Q303 (measured value transfer) in the measuring cycle that is causing the error: - Q303=0: Write the measured values with respect to the active workpiece coordinate system into the active datum table (activate in the program with Cycle 7!). - Q303=1: Write the measured values with respect to the active machine-based coordinate system (REF values) into the preset table (activate in the program with Cycle 247!). - Q303=-1: Measured value transfer is undefined. This value is automatically generated by the TNC when you download a program that was written on a TNC 4xx or with an old software level of the iTNC 530, or if during the cycle definition you skipped the prompt for the measured value transfer with the END key. [884] 10/2023
Source: HEIDENHAIN NC Error Messages — TNC7/640/620/320/128, CNC PILOT 640, MANUALplus 620 (10/2023)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Heidenhain TNC Series CNC Alarms
Heidenhain controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code 280-0436 on the TNC Series CNC identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Heidenhain's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 4497 Heidenhain TNC Series CNC codes.
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