I was wondering if someone could clarify / correct my understanding of MSG block on PLC5 / SLCs / ControlLogix platforms.
MSG blocks are asynchronous to scan time. I guess I am wondering how exactly this works. Are they messaging at set intervals (not unlike RPIs), or only when certain criteria are met?
If I have a read block in a ladder somewhere, is it continuously updating asynchronously or only updating when the scan happens to coincide with whenever the MSG block is polling the source?
What is a good method to handle a program that will require lots of messaging (heartbeats?)?
Thanks
MSG blocks are asynchronous to scan time. I guess I am wondering how exactly this works. Are they messaging at set intervals (not unlike RPIs), or only when certain criteria are met?
If I have a read block in a ladder somewhere, is it continuously updating asynchronously or only updating when the scan happens to coincide with whenever the MSG block is polling the source?
What is a good method to handle a program that will require lots of messaging (heartbeats?)?
Thanks