Code 26026: Axis %1 SINAMICS drive parameter P2038 value is not allowed.
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical Axis %1 SINAMICS drive parameter P2038 value is not allowed. 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 Definitions: For SINAMICS drives only: The interface mode, which is set via drive pa rameter P2038, has not been set to SIMODRIVE 611 universal. The alarm can be disabled by MD 13070 $MN_DRIVE_FUNCTION_MASK - bit15. However, the following must be noted: - The device-specific assignment of the bits in the control and status words may be different. - The drive data sets can be created at will, and need not be subdivided into groups of 8. (For details see also SINAMICS Commissioning Manual). So the parameters of motors 2-4 may be incorrectly assigned. Reaction: NC not ready. The NC switches to follow-up mode. Mode group not ready, also effective for single axes NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm. Remedy: - Set P2038 = 1 or - Set P0922 = 100...199 or - Set bit 15 of MD13070 $MN_DRIVE_FUNCTION _MASK (note the boundary conditions, see above) and execute a Power ON in each case. Program Continuation: Switch control OFF - ON.
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 26026 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.
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