Code 202099: <location>Trace: Insufficient Control Unit memory
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical <location>Trace: Insufficient Control Unit memory 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
Message value: Drive object: All objects Reaction: NONE Acknowledge: NONE Cause: The memory space still available on the Control Un it is no longer sufficient for the trace function. Remedy: Reduce the memory required, e.g. as follows: - reduce the trace time. - increase the trace clock cycle. - reduce the number of signals to be traced. See also: r4708 (Trace memory space required), r4799 (Trace memory location free)
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 202099 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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