New AC_StepProgram instruction, anybody using it yet?

[Hoobs]

NJ501-1300

Has anybody started using the (relatively new) instruction on the NJ/NX series, AC_StepProgram?

There is a structure variable used to provide the details of all steps of all programs (profiles) that you would want AC_StepProgram to manage.  It will calculate ramps, holds, soaks, etc., and move the setpoint around as necessary to implement each program/profile.  If ya need to do these things, it looks like a *big* headstart...  I'm glad I found it before I wrote a pile of code to do the same things!

My question: The structure variable used to provide the details of all the steps is an InOut variable.  For the life of me I can't figure out why, or if there is any scenario where the instruction would actually change anything in that structure.  There are other variables that I believe are all it needs to maintain state between task cycles.  Does anybody know why this is an InOut variable instead of just an In variable?

If you're wondering: This is important to me because I'm building a system to control several dozen closed loop furnace systems.  If need be I will replicate all 5 of my processing profiles to each one of the loops, but I was hoping to avoid that if AC_StepProgram doesn't actually change anything in the structure.

Thanks!
Hoobs

[innoaloe]

I never used it, but referring to the manual (screenshot here...) you can see that the TimeWidth and ReachSP values might change depending on the parameter you've input and the Step Number. I think this is to prevent any unintentional behavior due to improper parameter settings.

[Hoobs]

Thanks Inoaloe!  It turns out in my situation I'll not have things set up that way, so I'm going to try to just have a single one of these structures, set to be a constant, and see what happens.  If it doesn't work, I'll report back here.

[Hoobs]

Am I the only person on the OMRON forum these days who is using the AC_StepProgram instruction?  If anybody else is using it, and is getting success, please let me know here or PM me.

I'm using it heavily, and I currently believe there is a bug (or multiple bugs) that are preventing this instruction from correctly recovering after an unexpected power cycle.  I have also failed to ever see the StartAtPV option to the instruction ever do what it is advertised to do.  I'd like to hear what other folks are doing with this instruction, and if anybody has tried to put together a power hit recovery strategy for a system that includes this instruction..

Thanks!
Hoobs

Edited December 28, 2017 by Hoobs

[lostcontrol]

I’ve never used it, not have no idea on what it even does.

But, wouldn’t it be the implementation for the recovery, rather that a fault of the instruction itself.?

Unless of course the manual says that it can deal with powe failure events.?

[Crossbow]

Never touched it, never heard of it.