In program comments can be made severals ways with IEC programming within PAC software depending upon the language for the POU.
Structured Text ST:
(* Everything inbetween parentheses with star is a comment
and can be a multiline comment
These will automatically change to italic green font by default*)
This method is a good way to comment out multilines of Structured Text programs during debug quickly.

// Single line comments can be started with two forward slashes
example:

Ladder Logic LD:
Right-click to add a label and within the label either the // or the (* *) format can be used:

Network rungs can be commented out by right-clicking and selecting Toggle Network Comment State. Note this is done on the left side with the network rung number.

Continuous Function Chart CFC:
Comments can be made using a comment box:

Note: User documentation can also be included of any file type in addition to networked documents. For details see this FAQ:
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