Rockwell- IO Forcing management

[dalporto]

Hi.


This is the first time I do a project with Rockwell PLC from scratch.


I started a bit just building some AOI for a couple things I need to be sure it was working against InTouch.


Now I'm looking into being able to force whatever I need to force during commissioning.


I mostly used M340 and M580 over the last 10 years and nowadays we can force whatever we please with a M580 so this isn't even is an issue anymore when we cannot get the actual status from the field to test a logic.



Rockwell is still quite different. I don't want to double-up every tag I have just in case I need it during commissioning. I'm not quite sure yet what I can force but it look mostly like only the physical IOs; if I have a tag in between that is being written somewhere I cannot do anything with it.


What are you best practices about that?


Thanks.

 

[I_Automation]

Personally I don't ever force IO.


For an input I branch around it and put XIC Toggle_To_Test_Input[200] and just toggle that bit to test.


To 'force' an output ON another branch around the whole rung with its test bit. To Force an output OFF I XIO another test bit right before the output.



To make sure nothing is left ON I create a conditionally called subroutine that unlatches each one I put in and then unlatches the bit I toggled to run that subroutine. When I'm done I toggle that to clear all forces.


Also, if something happens in the future and an IO needs forced until something is repaired I can toggle that bit (as long as it's not a safety issue)

 

[dalporto]

Personally I don't ever force IO.


For an input I branch around it and put XIC Toggle_To_Test_Input[200] and just toggle that bit to test.


To 'force' an output ON another branch around the whole rung with its test bit. To Force an output OFF I XIO another test bit right before the output.

Yeah, that's what I did today on a live setup but I only had 2 to test.


It looks that I'd need a lot of these to build an "acceptable" simulator. But for wired IO I'm already covered with my remap blocks (I start the simulator and every 16 IO have an INT / WORD that I can modify). I'm looking more for some of the "software" bits in between.



What do you use for AI? In Schneider I use a selector block in a FBD section with a tag starting with SIM_ on each (I usually don't have many AI). I'm not sure how to proceed with Logix yet.