Need PLC pgm for one logic

sailaja · Sep 7, 2012

Hi,

iam new to this programming and now i have started to learn this on our company only with the help of my trainee.
i need one help on this.
the trainee gave me one logic mentioned below

there are 3 motors
motor 1 should run for 1 minute and motor 2 & 3 should be in off condition
if motor one stops after 1 minute then motor 2 shold on automatically and remaining 2 motors in off condition
then if motor 2 is off then motor 3 should on automatically..if motor 3 off motor 1 should on automatically...all the 3 motors should run for 1 minute time span only...
can u pls help on this with in one hour.
iam waiting for this logic.
allen bradley plc iam using

alan_505 · Sep 7, 2012

What model of Allen Bradley PLC are you using this will help people to help you.

Also show us what you have already done and we can help even more.

Most people on this site will not do your homework for you, we will help you if you show us what you have done.

Alan

sailaja · Sep 7, 2012

Hi

ok.

iam attaching the pgm which i have written for one motor

in micrologix 1000 i have used for writing

alan_505 · Sep 7, 2012

That does not look like a AB program.

sailaja · Sep 7, 2012

Need Help on AB logic

Hi,

pls find the attachment saved in word file for your reference

VAN · Sep 7, 2012

What is suppose to start this and stop this?

chavak · Sep 7, 2012

Welcome to the forum

Understand this exercise is for learning purpose only.

Think this way

1. Each Motor runs for 1 minute - so total 3 minutes
2. Use a self resetting timer of 3 minutes
3. Read and understand about comparison instructions
4. Compare timer values for 0 ~ 60 seconds - motor 1 ON
5. Compare timer values for 61 ~ 120 seconds - motor 2 ON
6. Compare timer values for 120 ~ 180 seconds - motor 3 ON

Regards

VAN · Sep 7, 2012

I would just use a counter...

Start some how (magic)
Count = 1 -> motor 1 start
Timer = 60 seconds -> count
Count = 2 -> motor 2 start
Same Timer starts over = 60 seconds -> count
Count = 3 -> motor 3 start
Same Timer starts over = 60 seconds -> count
Count = 4 -> mov -> Count = 1 -> motor 1 start
(goes forever... because no start/stop conditions)

Also, I'm under the assumption you have three outputs, the outputs will only energize if the count matches that output. When that output is not energized it will be off.

I dunno, this is how I see it, then you only have one counter, one timer, and three bools.

Lancie1 · Sep 7, 2012

Sailja,

Your program in "Mtr.DOC" is too complicated. Do not use dangerous Latch and Unlatch instructions to control motors (in a beginner program). You only need 1 timer because your complete cycle time period is 0 to 180 seconds. Now, how could you make it even simpler and still meet all the conditions?

(This is NOT a MicroLogix 1000 program, so you will need to change the addresses, the time base, and the timer Preset value to make it work).

sailaja · Sep 8, 2012

Need PLC pgm

with the help of ur logic diagram i have replaced the reset options in place of LIM for my pgm..but its not working....

can u pls give any other option with out including counters and mov functions.

OZEE · Sep 8, 2012

Can you make an attempt first? Our practice here is that we do NOT do your homework for you...

sailaja · Sep 8, 2012

Need PLC pgm

hello,

iam not asking you to do my home work...iam asking you the help which was not getting for me to do...i have already done the pgm and attached the document for your reference also...later Mr.Lancie sent the logic and i have made attempt on that one also..its not working if i replaced LIM with reset timer option...so that i have asked you to give another logic...

DwSoFt · Sep 8, 2012

sailaja said:
hello,

iam not asking you to do my home work...iam asking you the help which was not getting for me to do...i have already done the pgm and attached the document for your reference also...later Mr.Lancie sent the logic and i have made attempt on that one also..its not working if i replaced LIM with reset timer option...so that i have asked you to give another logic...

he is asking you to show the latest code you have written that still is not working. then we can compare the 2m and see if u are on the right track or not, and help you further.

Lancie1 · Sep 8, 2012

With the help of ur logic diagram, I have replaced the reset options in place of LIM for my p[rogram]..but it is not working....

Perhaps you did not understand HOW it is supposed to work. The LIM instruction is not an output-type instruction, but instead is a COMPARISON instruction. LIM will not directly replace OTL and OTU instructions.

The goal here is for YOU to learn how to write programs. If you would make a "Print Screen" JPG picture of the parts that are not working, then I am sure that all of us together can figure out WHY it did not work.

yasirkhi · Sep 8, 2012

Motor logic

Sailaja,

Have a look these sample program using LIM as Lancie mention. It is simple and good.

Need PLC pgm for one logic

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