Additional instruction set functionality

Programmable Logic Controller (PLC) vendors can implement additional functionality through instructions that are not specified in the specification.

Examples of extended instructions are instructions for diagnostics, PID loop control, motion control, and data file manipulation.

Because extended instructions are not defined by the IEC61131-3 specification, compatibility between different PLC vendors' implementations cannot be guaranteed. Consequently, using the instructions might hinder the transfer of logic between vendors.

Micro800

controllers and

FactoryTalk Design Workbench

provide a suite of IEC61131-3 compliant instructions. The physical representation of the instructions reserves their look and feel with the existing systems to reduce the training costs associated with working in the environment.