Attention

IronPLC implements many parts of the IEC 61131-3 standard and is working toward full Structured Text support. Key features still missing include ranges, enum and I/O mapping.

V9012

Code

V9012

Message

VM call frame stack exceeded maximum depth

The VM call frame stack exceeded the maximum depth while dispatching a CALL or function-block invocation. The VM uses an explicit call frame stack to bound recursion, and this limit was reached.

This typically indicates unbounded recursion in the PLC program or a call chain deeper than the VM’s configured maximum. Check the program for recursive function or function-block calls.

If the program is not recursive and genuinely requires a deeper call chain, report this at https://github.com/ironplc/ironplc/issues with the source program so the limit can be reviewed.