Can I have some help?

[Lancie1]

So far it does not appear that N7:0 does anything important, so your program probalby will run great with or without N7:0 being set to 0 or anything else. To verify that, do a search and FIND ALL cases of N7:0, and see if the value in N7:0 is used for anything (other than maybe a test of the I/O during the initial program set-up).

 

[josesaucedo]

Here is file LAD3.

 

[josesaucedo]

Here is more of it.

 

[josesaucedo]

Here is the rest of it.

 

[Lancie1]

Looking at how N7:0 is used, it is an important part of the program, and is being used as a Step Relay, with defined Steps form 0 to 999. The used Steps that I saw were: 0, 2, 3, 4, 5, 9, 10, 11, 12, 13, 14, 15, 16, 17, 50, 999.

A helpful thing would be to write a description for each of these steps and include it on one of more rung comments. Then you would be able to figure out if the various MOVES to N7:0 are correct, or have been changed over the years so that some are incorrect.

I AssUMe that N7:0 = 0 is the IDLE or not-running state.
999 = LAST STEP maybe, or error, or alarm ?
50 = ?

 

[kwade]

I haven't looked at the whole program yet, but based on what I have seen, you should be able to simply ignore the first 2 rungs, since they appear to be disabled.



-Eric

The first two rungs appear to be *monitor* rungs.
I have seen this approach used where the hardware is NOT in front of you and/or the software does not provide an easy way to view all physical I/O in table form.
Also, I have known a few programmers to do this as a matter of 'style.'

 

[pino2003fr]

Thanks Eric,
Can I removed the first instruction I:0/0 XIO? Some thing is not right because no body has access to this PLC program, in fact, this is the first time I connect to it. It's been like that for many years, or unless something changed after the power drop I had. Could that be possible?

Thanks.

hello everyone
in my opinion move I:0/0 XIC because E-stop it normally close contact and, may you have to change on LAD3 REG 000 from XIC I:0.0/0 to XIO I:0.0/0

 

[pino2003fr]

So far it does not appear that N7:0 does anything important, so your program probalby will run great with or without N7:0 being set to 0 or anything else. To verify that, do a search and FIND ALL cases of N7:0, and see if the value in N7:0 is used for anything (other than maybe a test of the I/O during the initial program set-up).

i think dose mater N7:0 it always true because E-Stop on Lad 2 Reg 0005 it most the time true when the machine up and running
if you go to N7:0 data table N7:0 it always 0 doesn't matter if you try force it from different sources stay 0

 

[Eric Nelson]

The first two rungs appear to be *monitor* rungs.
I have seen this approach used where the hardware is NOT in front of you and/or the software does not provide an easy way to view all physical I/O in table form.
Also, I have known a few programmers to do this as a matter of 'style.'

I agree 100%. Notice how the I/O is sequential. I should have picked up on that since I used to do something very similar to monitor my bit driven sequential logic, back in the days when an HMI was a 'luxury'.

A bit odd to precede it with disabling logic, and end with a move, but whatever.



-Eric

 

[leighigh]

I would not change anything in the program untill you understand it fully. I have never seen a program that has been running just up and change by its self. The first two rungs are used to monitor the sequinceing of the machine. Find were the sequince stops and you will find your fault.

 

[leighigh]

It looks like the clamp retarcted input I:0/10 is in the wrong state and will not allow the sequince to start.

 

[Lancie1]

I think does mater. N7:0 it always true because [of] E-Stop on Lad 2 Reg 0005. It most the time true when the machine up and running

Yes, I changed my mind after Jose finally posted the rest of the program. I think that N7:0 is being used as a Step relay to track the status of the process. See my Post #20 here:

http://www.plctalk.net/qanda/showthread.php?t=79407&page=2

 

[brstilson]

Thanks Eric,
Can I removed the first instruction I:0/0 XIO? Some thing is not right because no body has access to this PLC program, in fact, this is the first time I connect to it. It's been like that for many years, or unless something changed after the power drop I had. Could that be possible?

Thanks.

Has the machine constantly had power on it, like 24-7? The only thing I'm thinking is maybe there's an EEPROM chip inside and it's set to load that program on power-up, someone troubleshot the machine long ago, but didn't save their changes to the chip. That's really the only scenario I can imagine of the program actually changing. Otherwise programs don't just change themselves. That said, if there is an EEPROM or some type of memory card on this processor, make sure you save to it when you get the machine working.

 

[pino2003fr]

Yes, I changed my mind after Jose finally posted the rest of the program. I think that N7:0 is being used as a Step relay to track the status of the process. See my Post #20 here:

http://www.plctalk.net/qanda/showthread.php?t=79407&page=2

thank i didn't see post 20 , sorry loll