This is a working ladder version, push start, the conveyor will run unlit LS1 is tripped, the conveyor will remain stopped until the LS1 is reset (object removed) and after 5secs the conveyor will resume/repeat.
Max.

 

Thanks Max I will try that

 

So did you try it?
Max.

 

PLC001 are you studying at college, if so which one. I am doing my HNC at the moment at southdowns college. I have to program a PLC, im also studying a separate course online that should give some certificate.
there is a plc at the college sounds just like yours. I have a basic program for it. I know you require a few timers. are you sensing three items. to of same size but different width and one of smaller size.
this is what I was playing with at college. three pushers that push the item form the conveyor belt. the two sensors sense the two of the three different items by size. two items are the same size but have different widths. you have to determine the difference of width between the two to operate a third pushing device.

 

I tried it on the in-house Mitsubishi and it ran fine? Monitor mode is essential to track any problem.
It helps if you explain where the problem was?
Max.

 

If it did not run at all may be it was because you did not use a N.C. stop button, if so you can either change the ladder logic for the P.B. input or change the P.B. itself.
Max.

 

In the ladder I posted X1 is the stop P.B. and should be a normally closed P.B., if N.O. then change X1 to a NOT X1 function.
The sensor limit SW is X2.
The master control relay M0 on the left has to be there for the Start - Stop PB's to be active.
M0 should latch in when the Start PB is pushed.
If you have the monitor feature, you can see exactly where any problem lies.
Max.

 

On the S/W I have, you take the cursor to the left hand side rail and use the N.O. contact insert.
The first rung output is the MCR itself.
Max.

 

You would need to consult your manual for the MCR relay inclusion, you should have it.
I ran the program with the I/O hooked up and it ran fine.
The screens are a little hard to see, I will take a more in depth look when I get back today.
Max.

 

Make a print out of the actual ladder you have and post it.
Max.

 

Is it not possible to do this without an MCR relay ?

Yes of course it is possible, just that it can be more efficient and also should be something that should be learned.
Your PLC should be capable, I don't recall any that did not include that instruction.
What you could do is use the ladder that I previously showed that worked and instead of MCR use a M3 output and include a N.C. M3 ANDed in every rung.
Max.

 

Ok so the Master control and reset is a more efficient method. Thanks ill give that a go

 

Make sure first your stop and start rung works OK whatever method you use for the Control ON/Stop.
Max.

 

You should be able to just modify/adapt the standard Alarm flasher circuit.

| ... X0 .... T1
|----| |-------|/|------------------(T0 K10)----|
|
| T0
|----| |----------------------------(T1 K10)---|
|
| T0
|----| |--------------------------------(Y0)----|
|

Max.

 

Did you try it first as shown? This is a industry standard way of embedding a Panel light flasher (T0) where ever it is needed in the ladder.
Max.

 

Yes i tried it the way it is. However I had to hold the start button for 5 secs (changed it to K50) before the conveyor went for 5 secs. I aim to push my start button and it automatically drives the motor for 5 seconds then repeats this 10 seconds later. So on for 5 sec sand off for 10 secs. Any ideas on how i alter this ?

 

If I get chance today I will enter it and try it.
Max.

 

ok thanks a lot

 

I had a couple of Minuit's I winged this off, it should work OK or at least adaptable.
BTW If you intend using Mits PLC's in the Future, I definitely recommend you get the Book by John Ridley on Mitsubishi PLC programming.
Max.

 

thanks, ill give that a try