looking for a pulse stretch fcn

I'm looking for the pulse stretch function for the Omron CQM1H PLC.Or does this model even have it? Thanks in advance.

Catch a pulse (off to on transition). Latch an internal memory coil and, at the same moment, start a timer. When timer expires, unlatch the coil.
That's all.

LadderLogic

If the pulse is too fast you canot catah him.You need high speed input
or interrupt.

Cruise13

CQM1H input refresh is 8ms you can decrease it up tp 1ms depend on your cycle time.

If you work with CX it very esey to do from PLC set up.
If you work with Syswin you need to set DM 6620-6627. Read the manual first, page 13 CQM1H programming manual book.
You can also use Interrupt function too.It more complicated.

If you still have problems came back I will try to help.

Yes, Arik, I should have elaborated on my "catch a pulse" line. There are many ways of doing that and you have covered them well. Thank you.

Thanks.

I'm doing a student project on a model of a substation automation system. I'm trying to make a PLC program that takes care of switch interlocking and blocking that is foolproof (well, at least I hope so...) and I want to catch all switch inputs, regardless of the brevity of the pulse. This is so when testing is done, timing won't be very crucial.

But now that I look at it, I will still need help on developing interrupt functions for taking care of relay tripping. I can't seem to quite grasp it, and staring at the manual doesn't help.Care to give example/s for interrupt functions?

Thanks again.

Interrupt programming may help.
I have not used the CQM1H for this type of project before. Normally use the CJ1 or CS1. If my memory serves me correctly, the input filters etc are much easier, and better, to use in the latest processors.
I have done this type of project with the old C200HS. It had a really slow scan time compared to the modern processors. The rule of thumb is allow for the pulse to be at least twice the length of the scan time.
I have had to use external high speed timers to extend pulses before today. Perhaps these would help.
beerchug

The only hardware "pulse stretcher" that I know of is the 2288 module from PR Electronics.
I use it for stretching a sub 1 ms pulse to 50 ms so that the PLC can see it with no need for interrupts or special fast inputs.

Thanks, y'all.

I stared one more time at the manual, but this time serendipity came to me.

So, to make sure I understand correctly, to implement interrupts:

-input # (00000 to 00003)----INT(89)
CC = 000 (for masking and unmasking ints)
or 001 (for clearing ints)
N = 000
D = 000x where x = 0 to F (in hex)

and since input # corresponds to subroutine # (I know how to do this already...) [is D in the correct form? 'coz that's where I'm not totally sure.]

Now, I've got one more question...since I'm probably gonna want the interrupts enabled throughout the execution of my program, then I will no longer need to use the mask interrupts function? Am I right?

Thanks JesperMP, but we're trying to minimize costs as well. Anyway, I think my adviser would have me go with this procedure instead.

Thanks again.