Code 27091: Error in data cross check NCK-PLC, stop of %1
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical Error in data cross check NCK-PLC, stop of %1 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 = Extension indicating the monitoring channel that triggered the stop Definitions: The monitoring channel specified in %1 (NCK or PLC) has triggered a stop D or E (depending on the parameterization in MD $MN_SAFE_SPL_STOP_MODE ). The alarm 27090 provides further information about the cause for the stop D/E. Reaction: Alarm display. Trigger a STOP D/E (settable via MD $MN_SPL_STOP_ MODE) on all axes with safety functionality, as soon as the SPL start-up phase (MD $MN_PREVENT_SYNACT_LOCK[0,1] unequal to 0) is completed. Remedy: Evaluate the alarm parameters of alarm 27090 and am end the SPL, or check the I/O modules/wiring or the internal SPL interfaces to the sa fety monitoring channels in the NCK and drive SIMODRIVE611D. Program Continuation: Clear alarm with the RESET key. Restart part program
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 27091 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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