Code 231-E028: CC%2 MB/PLB does not respond. Device ID: %3
Issue Description & Safety Warning
The Heidenhain TNC Series CNC has triggered a critical CC%2 MB/PLB does not respond. Device ID: %3 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] - HSCI components with functional safety (FS) no longer responds (B channel): MB machine operating panel or PLB 6xxx - Component was separated during operation with the HSCI bus - 24 V NC power supply of the component was interrupted - The entered device ID provides information on the affected parameter: 5 = System module on PLB 62xx FS 7 = MB 6xx FS 15 = Expansion PLB (without system module) PLB 61xx FS, PLB 60xx FS 17 = Integrated PLB of the UEC controller unit - Faulty firmware of the PLB or the MB [Error correction] - Check the MB and PLB in the HSCI bus diagnosis - Save service files - Check the HSCI connections - Check the 24 V power supply of the MB and the PLB - Inform your service agency [552] 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 231-E028 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-E028.
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