Code 231-93E0: PWM frequency greater than 5 kHz requires double
Issue Description & Safety Warning
The Heidenhain TNC Series CNC has triggered a critical PWM frequency greater than 5 kHz requires double 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
speed %1 [Cause of error] - If the PWM frequency selected in the "ampPwmFreq" machine parameter is greater than 5000 Hz, the machine parameter "ctrlPerformance" must be set to Double Speed [Error correction] - Either reduce the PWM frequency in "ampPwmFreq," - or set the "ctrlPerformance" machine parameter to Double Speed - Inform your service agency
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 231-93E0 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 231-93E0.
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