ISPSoft not working as it should

[EVentomar]

Hello mates!!

I'm a few days trying to put this to work but I can't.

https://prnt.sc/hIlJz-iQR8B7


First of all, as soon as the RUN mode activates, Y0 activates also. So when I press X0, Y1 activates.

https://prnt.sc/ZqQXzed2thEY


But when I release, instead of Y2, Y0 becomes active.

https://prnt.sc/ZqQXzed2thEY

Going back to the same initial state.

 

[2rlp]

What is it that you are trying to do. As per your software, only the operation you have mentioned will take place.

 

[EVentomar]

Y'x are cicles. X0 is a button to advance to another cicle. Everytime I press the button it should go to the next step.

But apparently, the rising border is not working. It it going thru all the steps with only one press.

 

[drbitboy]

ISPSoft not working as it should

This is the clearest, though indirect, statement of the problem


I.e. the problem is the programmer's presuppositions/assumptions that

• the PLC "should" do what they WANT it to do,
• and the PLC is not doing EXACTLY what they TOLD it to do.

The only way to programming success in any environment is to invert that presupposition/assumption.

PLCs will always do the latter i.e. what I tell them to do.


So only by telling (i.e. programming) them to do what I want them to do will the PLC do the former.

Until I inculcate those last two statements into our very essence, I am wasting our time.

 

[drbitboy]

Y'x are cicles. X0 is a button to advance to another cicle. Everytime I press the button it should go to the next step.
But apparently, the rising border is not working. It it going thru all the steps with only one press.

Reverse the order of the rungs, and then please come back and tell us if that worked (it will).

Caveats

1) I assume

• if the button for X0 is pressed, then the value of X0 is 0, and
• if the button for X0 is released, the the value of X0 is 1

but it will work either way: if the sense of X0 is the opposite (i.e. X0=1 for pressed, X0=0 for released), then the advance to the next circle will occur when the button is released.

2) You may need a debounce on the button that effects changes to X0.

 

[drbitboy]

To be more robust, it may be advisable to have the rising edge of M1002 (on original [Network 1]) execute resets of Y1 and Y2.

 

[parky]

As far as I can see the problem is a rising & falling edge i.e. pulse contact will be on for one scan or off for one scan PLSR or PLSF (Pulse rising or pulse falling) what you need is for the pulse to be reset from the state before the next rung.
it looks like you are trying to do running lights sort of.
so it turns on each output i.e. Y0 first, then Y1, then Y2 every time the button X0 is pushed.
Write down the actual sequence i.e.
Initial state (I am assuming M1002 is first scan as I don't know ISPSoft)
Y0 is turned on
When the button is pressed Y1 goes off Y1 comes on etc.

 

[EVentomar]

Thanks for so many advices DrBitboy!!!

Actually, I found out the error. Once it went off, it would complete all the cycles because X0 or X1 would still be on for this scan. I need to reset them as soon as I change cicle.

Exactly what parky said.

 

[parky]

One of the best ways (not the only way) is to use say a counter & compares of the counter value or possibly an integer that you increment.

 

[drbitboy]

Thanks for so many advices DrBitboy!!!

Actually, I found out the error. Once it went off, it would complete all the cycles because X0 or X1 would still be on for this scan. I need to reset them as soon as I change cicle.

Exactly what parky said.

which is why reversing the order of (the execution of) the rungs will also fix it, because ... wait a minute ...

whoops, you also need to put the X0 falling edge detections before (to the left of) the Yx checks.

that way only one step will complete on any single XP falling edge, because that falling edge instruction is actually looking for the falling edge of the logical AND of the tag AND the input rung state.

 

[drbitboy]

what is interesting is that the individual rungs and choice of instructions were fundamentally correct, but the order in which those components were arranged to be executed was not.

this reinforces the idea that a large part of PLC programming is about time.

 

[AlfredoQuintero]

parky, drbitboy, it is impossible to exaggerate your dedication and generosity. And of course your PLC programming skills are superb.

 

[drbitboy]

I looked at OP's original images again, and something does not make sense; see below.

​

 

[drbitboy]

whoops again, it is yet more complicated: because the AVANÇA button advances either from Y0 to Y1, or from Y1 to Y2, or from Y2 back to Y0, it is not as simple as only inverting the order of the rungs. It's not overly complex, but it not as trivial as I thought.

Also, it appears that, once M1002 has a rising edge and starts the cycle with Y0=1, there is no way to return to the state where Y0, Y1, and Y2 are all 0 again.

Finally, in order to help OP, there needs to be more information provided.

 

[parky]

This is how I see it, the assumptions are:
You set Y0 on PLC going to run
Then every time you press the button (X0) it will set the next output Y1 & reset Y0 & so on
When Y2 is on & the button is pressed it then it reset Y2 & sets Y1 (sort of running lights).
Note: used a pulse bit rather than the pulse of the input (usually inputs cannot be reset within a program),
Because a pulse flag will be on for one scan need to reset it directly after setting the following output so it is off on the next rung.
Doing it in reverse order will not work if you need to go back to Y0 hence the pulse bit reset.
If you do not have a pulse output then create a one shot

LD X0 AND NOT M1 OUT M0

LD X0 OUT (M1)