Problem with simple Integer functions in Micrologix 1400

Paul Rasavage · Nov 22, 2011

For some reason, I cannot get even the most simple integer to integer function to work, e.g., (MOV N18:24 to N31:2).

I have also tried MULT:
MULT
Source A: 10
Source B: N18:24
Dest: N31:2

There are no errors that I can find, yet N31:2 is always 0 !!!

I have tried all sorts of things but for some reason I cannot operate on one integer and get the result into another register.

Any ideas?
Thanks!
paul

bce123 · Nov 22, 2011

can you post logic and i have to ask is the plc in run?

bce123 · Nov 22, 2011

also if this is in a sub rutine are you calling it?

Clay B. · Nov 22, 2011

bce123 said:
also if this is in a sub rutine are you calling it?

My bet is here. Either that or the PLC is in Program or Faulted. Or he is working offline.

Paul Rasavage · Nov 22, 2011

The PLC is in REMOTE RUN.

The logic is as stated:
one rung with a permissive bit --[ ]-- which I toggle.

--[ ]-------------|MULT |---
|Source A: 10 |
|Source B: N18:24| (which has a value of 12)
|Dest: N31:2 | (which always contains 0,
but should contain 120)

I am obviously missing the obvious, but I'm not seeing it.
paul

bce123 · Nov 22, 2011

try it without the permisive or force it on

Clay B. · Nov 22, 2011

Are you scanning the Subroutine that you are trying to do the math in?

Unless you wrote your code in Ladder 2 you need to have a JSR that runs the sub routine you have your math in.

TConnolly · Nov 22, 2011

Welcome to the forum Paul.

Can you zip your .RSS file and attach it to a post? The forum can usually home in on these kinds of problems in just a few minutes if we can see your program.

James Mcquade · Nov 22, 2011

your answer will always be zero when you place a zero back into the register.

If on rung 10 you do the multiply the answer is 120 as you say.

BUT, if on rung 30 you move a zero, copy zero , clear the register, or anything to make the result register a zero, then your answer will be zero everytime.

Remember, the last operation on the register wins.

regards,
james

Paul Rasavage · Nov 23, 2011

You guys were a great help!
It was in a subroutine that was being called, but the permissive wasn't set.
Once I toggled the permissive, the MULT executed correctly.
Thanks for the catch!
paul

Clay B. · Nov 23, 2011

Paul Rasavage said:
You guys were a great help!
It was in a subroutine that was being called, but the permissive wasn't set.
Once I toggled the permissive, the MULT executed correctly.
Thanks for the catch!
paul

unless you absolutly need to condition a subroutine call I would strongly suggest you do not do this. This is one of those things that cause all kinds of headaches with no real benifit for using them.

Problem with simple Integer functions in Micrologix 1400

Paul Rasavage

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bce123

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bce123

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Clay B.

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Paul Rasavage

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bce123

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Clay B.

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TConnolly

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James Mcquade

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Paul Rasavage

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Clay B.

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