Code 26106: Encoder %2 of axis %1 not found
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical Encoder %2 of axis %1 not found 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 = Encoder number Definitions: For PROFIdrive only: The encoder configured for the spec ified axis could not be found. For example, a PROFIBUS slave was configured on the NC but it is not contained in the SDB or defective hardware was reported for it. Reaction: Mode group not ready. The NC switches to follow-up mode. Channel not ready. NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm. Remedy: Possible causes: - MD 30240 $MA_ENC_TYPE not equal to 0 as a result of an oversight; the en coder should actually be simulated (= 0). - MD 30220 $MA_ENC_MODULE_NR entered incorrectly, i.e. the logical drive numbers were transposed and an invalid value is stored for this drive in MD 13050 $MN_DRIVE_LOGIC_ADDRESS (see next paragraph), or a drive number which does not exist on the bus was entered (check the number for slaves, for example). - MD 13050 $MN_DRIVE_LOGIC_ADDRESS contains val ues which were not configured on the Profibus (i.e. the values are not in SDB Type 2000) or different addresses were selected for the input and output slots of the drive in the Profibus configuration. - A fatal encoder error was detected during the sele ction of the encoder (encoder defective, removed), so that park status cannot be left (in such a case, this alarm is triggered instead of alarm 25000/25001 - please refer to them for other possible causes of the error). Diagnostics Manual (DAsl), 03/2009 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 26106 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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