new to PLC programming

I'm using the directsoft32 software and i'm new to PLC programming. I've looked at the tutorial and i'm still confused. I've been able to turn one valve on and off using a timer and a simple test program. Using a counter how would I turn on multiple valves, then once one of my inputs reaches a certain value, make the counter advance one, and hence advance to the next step/process for the PLC? Is anyone familiar with directsoft32 software?

thx
Dave

Sorry, but your question is not clear.

For counters, each PLC brand has a different method for handling these. For most of them though, they will have an edge detecting "count" input that counts the number of rising edges. If the input is staying "ON", then you may be getting no counts.
The counter will also generally have a reset/enable input, that will have to be either on or off (depending on the manufacturer) for the counter to operate.

As for turning on and off multiple valves, I generally will program the ON conditions for each valve separately. It is possible to group them, but keeping them separate helps with troubleshooting and modifications.

Doug

This looks like a good application for the "drum timer" instruction. AutomationDirect.com's is easier to set up than most, and you can either have it event or time based. In your case you can use the counter to trip the events. The manual is pretty good on explaining use, but you will have to play around with it a little.

Another technique you should look at is using compares. For example, you can use the accumulated count (CTA12 for example is the accumulated count for counter 12) with equal, greater than, or less than comparisons to a counter or a V-memory location. This can turn on a coil to falg a step as completed.

You definitely want to keep your outputs separate rather than grouped - it does simplify troubleshooting.

I agree with Tom. The drum timer from AD should be pretty straight forward in this situation, but you will probably have to tweak it a little. I've not used this method much, but it's not too hard. The second method he mentioned is more of a standard programming practice here. Keeping the outputs seperate is if nothing else, just good safe practice. I couldn't tell you how many times ganging up outputs caused problems for some of the existing software I had to fix when I started here. If you have any questions on the second method, I can probably offer some help.

Don't forget

Don't forget to use Automation Direct's Tech Support. They are very good and they will walk you through any problem that you have.

Like the other two guys said- it sounds like a drum is going to fit your application pretty well.

One word of caution though- I've used a drum in another mfg's plc and when you do an online edit (don't thing AD allows this but anyway) the drum resets to Step 1. Not a cool thing to have happen to you when the application is on a 3 bed mol seive dehydrator

Oh... to elaborate

Since you are new to programming, Tom and Tag's recommendation on not grouping outputs is dead on. What they mean is this-

Don't do this-

--| |------(O1)
|
|--(O2)

where O1 and O2 are outputs

Instead do this-

--| |------(M)

where M is a memory bit. In a 505 it would be a C.

then do this

M
--| |--------(O1)

and then do this

M
--| |--------(O2)

Geez that was almost as bad as writing something in RSLogix

Well Rats

My little pictorial didn't work... Need to move O2 on the first rung out to the location just under O1

Everybody has trouble getting things lined up at first, Mike. The trick is, before you start the logic insert the word "ladder" surrounded by square brackets []. when done, insert "/ladder" inside brackets.

There is explanations for this on the site someplace.

Oh... well that's cool.

I've had some real problems with "staying logged in" too. Every time I come here I have to register. I added this site to my IE privacy settings so hopefully that will fix that. If not maybe adding it to my firewall will help...

Thanks

Check if you have 'cookies' enabled, at least for this site. I think that's how it remembers who you are the next time you visit.

Thanks. I added the site to my firewall program. It was blocking cookies. Now when I come back I'm me and I don't have to log in.