Attention

IronPLC implements many parts of the IEC 61131-3 standard and is working toward full Structured Text support. Key features still missing include structures and user defined function blocks.

Extension Library

IronPLC provides vendor extension functions, function blocks, and variables that go beyond the IEC 61131-3 standard. These extensions are commonly supported by other PLC environments such as CODESYS, TwinCAT, and RuSTy.

Tip

Extension library items require explicit opt-in via --allow-* flags or --dialect rusty. See Enabling Dialects and Features for details.

Functions

Function

Description

SIZEOF

Size in bytes of a variable or type (requires --allow-sizeof)

Function Blocks

No vendor extension function blocks are currently defined.

Variables

Variable

Description

__SYSTEM_UP_TIME / __SYSTEM_UP_LTIME

Monotonic uptime since VM start (requires --allow-system-uptime-global)