Code 7300: Problem with externally linked COA application %1 Index: %2 Additional information: %3
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical Problem with externally linked COA application %1 Index: %2 Additional information: %3 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 = Name of the COA application %2 = Index describing the problem that occured in more detail %3 = Optional additional parameter Definitions: A problem occurred while loading th e COA application. This problem is described in more detail by the parameters "Index" and "Additional information": Index == 1: The interface version of the COA applicat ion is incompatible with the NCK version. The additional information contains the inte rface version of the COA application. Index == 2: The heap memory requested by the COA appl ication is not available. The additional information contains the heap memory requested in KB. Index == 3: The $P_INCOAP parameters requested by the COA application cannot be created due to insufficient memory. The additional informat ion contains the heap memory requested in KB. Reaction: Alarm display. Remedy: Index == 1: The COA application is not executable in the current environment. Please inform the authorized personnel/service department. Index == 2 or.3: The memory requested by the COA ap plication will not becom e available until after another restart. This means that the alarm should no longer occur with a restart (NCK reset). Otherwise, there is a real memory problem, and the CO A application is not executable (see Index == 1). 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 7300 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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