NOP instruction equivalent?

[Lovell]

Is there an equivalent Rockwell PLC NOP instruction that is available for the M340 M580 Schneider PLC?

Thanks,

 

[JeremyM]

I'm fairly new to Control Expert and haven't seen an instruction like this.

You could substitute it with an instruction call that has no data side effect like moving a tag value into itself: MOV Tag Tag.

You could also use the EFB Toolkit to roll your own NOP elementary instruction. It's not a bad idea and would be easy to do.

 

[Lare]

Where you even need NOP which is no operation?

 

[JeremyM]

Where you even need NOP which is no operation?

Troubleshooting logic, logic substitutions, an effectively "commented out" rung, and so on.

 

[I_Automation]

What I always do on the SLC's and other platforms is add 3 tags for troubleshooting



B3:0/0 = AFI, unlatch it at the start of every scan
B3:0/1 = TRUE, latch it every scan
B3:0/15 = NOP



To make a rung false add XIC AFI
To branch around an instruction XIC TRUE
To use the NOP just OTE NOP

 

[Steve Bailey]

There are plenty of ways to to accomplish what you want. Whatever method you choose, do yourself a favor and include a comment to explain your intent. Your successor will thank you.

 

[Lovell]

Is there an equivalent Rockwell PLC NOP instruction that is available for the M340 M580 Schneider PLC?

I am using a Schneider PLC and I am trying to replace an existing coil with an operation that will not energize or de-energize that coil but I want to leave the rung in place as a placeholder with the existing conditions to set it. In Rockwell world I would just replace the coil with an NOP. I don't think my question came though clearly - I apologize and I hope this describes it better.

 

[Lare]

You can code allways true and allways false bits.
Rons signature have clue for one method.


http://plctalk.net/qanda/member.php?u=726

 

[Steve Bailey]

I am using a Schneider PLC and I am trying to replace an existing coil with an operation that will not energize or de-energize that coil but I want to leave the rung in place as a placeholder with the existing conditions to set it. In Rockwell world I would just replace the coil with an NOP.

Presumably just temporarily? Otherwise, what would you do with any XIO or XIC instructions with the same address as the coil instruction?
You could accomplish the same thing by readdressing the coil instruction to an unused address.
Not sure about Schneider, but in a GE/Emerson PLC you could apply a force to the coil without changing its state.

 

[Peter Nachtwey]

Is there an equivalent Rockwell PLC NOP instruction that is available for the M340 M580 Schneider PLC?

Thanks,

Can you move A to A?

 

[JeremyM]

Can you move A to A?

One easy way, agreed.

Probably throws cross-references a bit of a curveball, but nothing crazy.