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.

Variables

Vendor extension variables provided by IronPLC. These are implicit global variables injected by the compiler and updated by the VM at runtime.

Variable	Description
__SYSTEM_UP_TIME / __SYSTEM_UP_LTIME	Monotonic uptime since VM start