counter instruction ?s

[Ron Beaufort]

final exam is to remind me to prepare for my final test program i will be required to present and document

OK ... good enough story ...

if you need more help, consider posting the PDF file I sent you ... the forum members will be glad to give you a hand ... personally, I've got to run along now ...

incidentally, I remember changing the Preset in the Counter from 10000 to 5 ... I didn't want to run 10000 cycles to see how the program reacted ...

questions you need to consider:

(1) if you stop the auto cycle by pressing the stop button, do you want the Counter to reset? ...

(2) if the power to the system fails, do you want the Counter to reset? ...

be careful to follow the logic through for at least two scans after making any changes ...

HIGHLY SUGGESTED: get yourself a processor to play with if you intend to keep on in this trade ... you're NOT going to be able to get very far without a working system to play with ...

good luck with your studies ...

 

[plcnovice34]

busted on what?

 

[Ron Beaufort]

he's just messin' with you ... don't take it serious ... sometimes jokes don't come across that well in print ...

 

[plcnovice34]

Help is appreciated

I have to modify this program to not reset if power is lost or cycle is stopped before the set value of test. Program deals with a quality inspection issue

 

[plcnovice34]

Tahnk you mr. Beaufort, yeah they do not come across well. I am so new to the plc world , so much so, that i am still an infant in the crib.

 

[Ron Beaufort]

OK ... hint number 1 ...

what is the existing condition that makes the counter reset? ... here, I'll get you started:

we'll reset the counter when ________________ ...

note: the "trick" to this is to ONLY read and interpret the ONE rung that controls the RESet instruction ... if you start trying to "tie it all together" you'll be making this more difficult that it needs to be ... specifically, what does this ONE rung (in and of itself) "say" about when the counter will be reset? ...

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hint number 2 ...

what type of rung construction is responsible for maintaining the Auto Cycle Start bit B3:0/0 in the ON condition? ...

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hint number 3 ...

in an Allen-Bradley processor, what ALWAYS happens to this type of rung construction EVERY time that the processor starts up? (as in after a power failure has been restored) ...

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answer those "hint" questions correctly – then and ONLY then – will you be ready to figure out what DIFFERENT conditions you want use for triggering a counter reset operation ...

post your thoughts – the forum members will help ...

 

[Mickey]

See link below scroll down and go to "Sample Lessons" then view lesson 11.

By the way it would be helpful for you to view all the lessons in sequence but lesson 11 will help you with the latch in rung 000 and the reset of your counter after a power lose.

http://www.ronbeaufort.com/

Edit:

Ron types faster then I do.

 

[Rube]

BTW, I don't know if you wrote this code originally but you don't need the redundant T4:2/DN in rung 5. Not being picky....

 

[Ron Beaufort]

I'm pretty sure he didn't write it, Rube ... I think this is just a student exercise from his instructor ...

I didn't mention that "extra" instruction - or the field wiring of his Stop Button ... personally I think he's got enough on his plate for right now ... this would be a LOT easier for him if he had a processor to try it out on ...

 

[Rube]

...the field wiring of his Stop Button...

Yes, sir, I noted the STOP button too but not knowing if that was a aux contact off of a real-world E-stop, I let that one pass.

 

[Kick-It-Up]

BTW, I don't know if you wrote this code originally but you don't need the redundant T4:2/DN in rung 5. Not being picky....

I don't see a redundant xic, one is the seal-in the other for the Fault light which is only active after the fault time, how is one redundant?

 

[504bloke]

at 3.20AM
suggestion: can you post the actual exercise that the instructor gave you? ...

at 3.28AM
Ditto


And if someone has not already ask, post your program here and someone will take a look.

The suns in your eyes mickey

 

[Ron Beaufort]

actually you're quite right, Kick-It-Up ...

when I first glanced at it, I somehow got the impression that the second XIC wasn't needed – but you're correct ... they certainly intended that the Fault Light shouldn't come on until the timer ran through to completion ...

that's what I get for trying to answer forum posts while I'm working on paying projects ... got to quit doing that ... (the posts, that is - not the paying projects) ...

 

[Ron Beaufort]

The suns in your eyes mickey

take it easy on us, folks ... Mickey and I have reached the point where we've started getting older a lot faster than the rest of you guys ...

I hate to admit this – but this is a true story ...

I had so many irons in the fire a few nights ago, that I actually misspelled my OWN name ... I was printing my name for the return address on an envelope – and wrote out:

R-O-B instead of
R-O-N for my first name ...

I guess I was "thinking ahead" to the "B" coming up for "BEAUFORT" – but doggone it, misspelling my own name is a new trick ...

my wife says I need to slow down – but things have been so slow for the last year or so that I am NOT going to complain now that things are starting to pick up again ...

party on ...

 

[plcnovice34]

here are my novice thoughts: when cycle start pushbutton is energized auto cycle starts recline is timed up to 10 seconds then forward is timed for 10 seconds which completes 1 count .this action is perfomed to the desired 10000 in which the cycle counter xio dn bit is engaged which engages auto cycle xio triggering the cycle counter reset instruction. please do not laugh if i am in error