By Miles Nicholson
When designing a circuit, you may place modules or components down and not know what circuitry is ultimately connected to the terminal connections. This may result in the requirement to stretch the gap between two connection points to a greater distance to accommodate the addition circuitry. It also may mean that you have to split the component and move the 2nd split to another drawing.
If you split a component such as a PLC, the split parts of the symbol will not have a XREF attribute meaning that they will not cross reference each other visibly (internally they will be linked and cross referenced).