Whilst doing a small mod to a CP1L today, I had the need to use the UP/DOWN instructions in the ladder.

When I tested the code with the Simulator, everything worked as expected. When I tested in the PLC, the UP instruction did not work.

When I checked the manual, it says 'available all PLC's', but the CP1L is not listed, whereas the CP1H is.

The frustrating thing here is, that I was able to add the instructions with CX-P, and did not get a compile error, and was able to download with no issues.

Of course, I can re-code to suit, but using these instructions was a bit more elegant for this application...

Scott

This does not sound right.
I checked the combined CP1H / CP1L manual, and it does not list any restrictions on CPU type.
If CX Programmer lets you enter the instruction, then it should be OK.
Unfortunately, I cannot check on CP1L hardware until tomorrow.

Not to sound stupid, but how did you verified the instruction is not executed? How about the down instruction?

[attachmentid=7181]

Certain.
I have been able to prove the enclosed program and with CX-Simulator it works and on-line no.

I don't find contraindication in any manual.

(With a CP1L-L)

Must have slipped through the beta rounds!

What exactly does not work in this fragment of the code?
Did you try it as being the only code in the PLC? Prbably, the reason is somewhere else in the program.

Why are you using the UP/DOWN instructions??
Try using the differentiation UP/DOWN properties of the contact and see if this works online!!


UP ^

---------| | |-------

DOWN v

The program only consists of these you line.
Activating the first contact, the instruction UP will make as a DIFU or as a contact with upward flank.

Me alone it proved. . . . jeje

To see that Scottmurphy says.

PMCR,
That's what I thought, but when the rung did not execute as I planned, this was all I could put it down to. It does seem odd that CX-P will let you enter, but then it does not work.
Will be interested to see if it is a hardware issue, or my issue....




When I executed the preceding condition for the rung, it did not work.



Interesting, so it is not just me?




Because I was using a '=' statement preceding the UP instruction, and did want to use a DIFU, or @SET.
I would think the Contact UP/DOWN instructions would work fine, but as I said, I had to re-code, not a major, just a preference.


Will be interested to see some other comments/results on this.

Automation, have you found the same issue?

That works, I know because i have a program operating out there with it.

However, i was not aware of the restrictions with the UP/DOWN, thanks for pointing it it out Scott...

Scott

I finally got back to my hardware, and you are correct. The up / down instructions don't work.

Fortunately, as others have pointed out, there are ways to work around this.
These are also instructions that I find very useful.

Thanks PMCR,

Good to have it confirmed.
There are many ways to code the same thing, for this instance, these were quite useful. As you have also stated, there are work-arounds thanks to the no. of 1-shot instructions/options that Omron provide.


Do you work for Omron?

Yes, I do work for Omron.
My participation in MrPLC is as an individual, not as a vendor.

Aw, shucks. He's just being modest.

IMHO, those in tech support for any manufacturer should be proactively participating on this site, it is a great learning curve for us all especially when a curly one gets raised, not to mention the product improvement knowledge that they as a manufacuter can gain.

So cheers, to all that do !

Just another thought that I had, is there any other instructions that may/may not be available in this model?

I know typically, if certain instructions are required, the PLC is normally a larger model anyway. Would be good to know it there are anymore 'gotcha's', to save pulling out what hair some of us have left...