The process of creating a PLC symbol involves specified steps which must be carried out. A good basis for starting is to load an existing PLC symbol in the symbol editor and become familiar with the explanations of this example.
The sequence in which the pins of the PLC channels are placed is a very important aspect of this process. Pay very close attention to this later on.
Furthermore, there is only one wildcard for each cross reference and PLC text for all channels. The position of the other texts is determined by the distance of the wildcard from the first PLC pin. For example, if the wildcard for the cross reference is on the right of the first pin, then the cross reference for the second pin is positioned at the same distance as that of the wildcard from the first pin. This means that it is not possible to place the cross reference to the left of the pin for one part of the connection and the cross reference to the right of the pin for another part of the connection within a PLC symbol. One wildcard is available for the position of the cross reference and the PLC texts in each case. The relative position to the PLC pin drawn is transferred to all of the other channels. All wildcards are a component of the symbol and must be entered as general text.
The symbol which displays all connections of a PLC assembly (main element) in a clear way is designated as the main module. A single input / output or a group of inputs / outputs can represent an auxiliary module (auxiliary element). A PLC symbol (main module or auxiliary module) contains a certain number of channels which are combined in groups. Each channel can in turn have an unlimited number of connections (pins).