Mitsubishi A0J2 problem

[kerolarifen]

Dear All,

currently i have a problems with my mitsubishi PLC.
i'm using A0J2 (old PLC).

when the input is triggered,
the output remain same which is not activate.
even i try in simulation mode,
it still not activate.

here i attached the simulation image.

 

[drbitboy]

In the upper left, I see

   [U]|[/U]
N0 _ M21
   |

What does that do?

 

[kerolarifen]

In the upper left, I see

   [U]|[/U]
N0 _ M21
   |

What does that do?

thanks friend.
that was the solution for it.
already simulate it,
and it working now.

i don't see it before this.

thank you very much friends.

 

[drbitboy]

thanks friend. ...

You are very welcome.


I am humbled by how often a fresh set of eyes finds my mistakes (even occasionally my own after a night's sleep), so I am more than happy to pass on the favor. P.S. I have never worked with Mitsi stuff; maybe that is why I saw it?

 

[parky]

That is a MC (Master control) any code after it will only be processed if the relay is on so before that there should be an MC instruction and at some point later in the logic a MCR (Master control reset).
So to elaborate any code between the MC & MCR will only be processed when the bit in the MC instruction is turned on.

 

[drbitboy]

That is a MC (Master control) any code after it will only be processed if the relay is on ...

The sublime beauty of ladder is that that contact (NO; XIC) on the left-hand rail made that intuitively clear to someone with zero experience in the Mitsi domain, and who had never seen similar notation before.


Exactly as intended by the designers of ladder.


N.B. I'm not saying that that makes ladder superior - I dislike all programming languages - or anything like that; just it has its uses.

 

[parky]

I agree it does see a little weird how it is displayed, however, the reason for this is if it is a long bit of code it makes it a little easier to understand. My explanation is not very good I should have explained it is not a sort of jump over the code, if the MC relay is off any output in the ladder will drop off (they will not stay on like a jump round the code it is just a way of displaying the same as the code attached), so even if the logic is true on any of the rungs the resulting outputs will be false attached is the equivalent of the MC/MCR instructions. so in reality is just a contact driving multiple ladders.
Here is the equivalent in normal ladder doing the same job. M0 is just the equivalent of the MC/MCR instruction.