Code 26050: Axis %1 parameter set change from %2 to %3 not possible
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical Axis %1 parameter set change from %2 to %3 not possible 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
Parameters: %1 = Axis name, spindle number %2 = Index: current parameter block %3 = Index: new parameter block Definitions: The parameter block change cannot be performed without jumps. This is due to the content of the parameter block to be switched on, e.g. different load gear factors. Reaction: The NC switches to follow-up mode. Local alarm reaction. NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm. Remedy: In the following cases, the parameter block change is carried out via MD31060 $MA_DRIVE_AX_RATIO_NUMERA and MD31050 $MA_DRIVE_AX_RATIO_DENOM without an alarm, even with different load gear ratio settings: 1. If no position control is active (e.g. in follow -up mode or if spindle is in speed-controlled mode). 2. For position control with the direct encoder. 3. For position control with the indirect encoder (the calculated load position difference must not exceed the value indicated in MD36500 $MA_ENC_CHANGE_TOL). Program Continuation: Clear alarm with the RESET key. Restart part program Diagnostics Manual (DAsl), 03/2009
Source: SINUMERIK 840D sl / 840Di sl / SINAMICS S120 Diagnostics Manual (DAsl, 03/2009)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Siemens SINUMERIK 840D CNC Alarms
Siemens controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code 26050 on the SINUMERIK 840D CNC identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Siemens's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 4014 Siemens SINUMERIK 840D CNC codes.
Have a better solution?
Help the industrial community by sharing your repair experience for code 26050.
Need a searchable reference for more Siemens SINUMERIK 840D 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