Code 231-C350: Axis module %1 not ready
Issue Description & Safety Warning
The Heidenhain TNC Series CNC has triggered a critical Axis module %1 not ready 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] - Safety relay not on (e.g. connectors X71 and X72 of the UV, X73 of the HEIDENHAIN expansion board for Simodrive) - PWM bus cable interrupted - Interruption in the electrical cabinet - Defective axis module - PWM interface on the control defective - No pulse release for the axis module - Uz too high - 5V power supply too weak - Inverter not ready - Motor control board defective - PWM cable defective - Noise signals [Error correction] - Inform your service agency - Check the control and cabling of the pulse release - Check Uz - If the power supply is not regenerative, is the braking resistor connected? - If the power supply is regenerative, is the energy recovery activated? - Check the cable ground and shield - Exchange the power module - For P controls, exchange the interface card - Exchange the motor control board
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 231-C350 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.
Have a better solution?
Help the industrial community by sharing your repair experience for code 231-C350.
Need a searchable reference for more Heidenhain TNC Series CNC manuals?
We structure equipment manuals into searchable code, title, cause, solution, safety note, and source-reference data. Send a PDF and example searched codes when you need public pages, private search, or structured exports.
Space reserved for Google AdSense / Industrial Affiliate Links
Monetization target for 2026