Although the PLC is a central part of TrySim you will never see it. If you want to know how a PLC looks like you will have to look at the catalogues of the producers. The structure of a PLC simulated by TrySim is the following:
In the following the single parts are described. General knowledge of the function of a computer is required. We refer you to the extensive available specialized literature.
See also:
Naming the Inputs, Outputs and Markers