Technical introduction

The PLC library TF8400 TwinCAT 3 MTP Runtime represents objects (function blocks) for controlling and monitoring actuators and sensors in process technology. It is primarily designed for TE8400 TwinCAT 3 MTP Engineering, but can also be used independently.

The objects of the PLC library are divided into the following areas:

• ActiveElements (drives, valves, and PID controllers)
• DiagnosticElements (interlock indicators)
• IndicatorElements (sensors and displays)
• OperationElements (value specifications)
• InputElements (incoming process value signals)
• OutputElements (outgoing process value signals)
• ServiceElements (services)
• ParameterElements (parameters for services)
• PeaElements (provision of vendor information)

Access to the variables of these objects is controlled via the operation modes and takes place via:

• The internal logic variables have *Aut or *Int as a suffix
• When accessed via OPC UA variables, for example, the suffixes are *Op, *Man, or *Ext