Rockwell Automation 1775-KA PLC-3 Communication Adapter Module User Manual - Manual (Page 78)

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Chapter 5
5Ć4
Note that it is not always necessary to create a message procedure. If you
want to execute just a single assignment command that is no more than 76
characters long, then you can enter that command as part of the ladder
diagram message instruction (Table 5.A). If you want to execute more
than one 1775–KA command, or if a single assignment command is more
than 76 characters long, then you must create a message procedure to
contain those commands.
Also note that every message procedure must end with either an EXIT or
a STOP command. The EXIT command is normally preferred because the
STOP command is a more extreme measure that results in error 179
(Appendix B).