New to plc's

Hi all,
I figured I would introduce myself before asking some questions. I am from Reno NV. I dont know anything about plc's but am working on a project that would possibly require one. I have some electica experience in motor controls and vfd's as all the electrical work I do at work is with motor controls.

Here is the project I am working on. I am building a pop up target system that uses air actuators to stand the tagets up. I will have electronic solenoid valves to regulate what actuators get air to stand up. This is where I think a plc would come in but im not sure.

I will have 15-20 targets out at a time but will only need 5 to stand up in one round. I will alternate between targets so its not the same targets every time. I need one target to stand up at a time and be up for 8-15 seconds then go down and the next one come up. Is this do-able with a plc? Is thier an easier way to go about this? Am I able to program multiple sequences into a plc or can I only program 1 sequence at a time in?

Aslo is thier any sugestions on what plc to get? It isn't something that will run all the time maybe 6-10 times a year.

Thanks
Nate

Welcome to the forum. Yes everything you talked about you can do and more!

Ok cool. I have talked to a couple people that have systems like the one I am looking to build but they wont give out any info as far as plc stuff goes so thats why I am on here.

I have been doing some looking around at plc's and there's so many options is overwhelming. What are some plc's to look at? I have been told to look at the Click plc's at automation direct. Would that be a viable option for this project?

Welcome to the Forum!

This would be a good application for a PLC. I am partial to Allen Bradley PLCs, but everyone has their favorite. I do believe Allen Bradley is easier for someone new to PLCs.

You need to make some decisions ahead of time.

120VAC or 24VDC Outputs etc.

There are some relatively inexpensive MicroLogix 1000 PLCs, and there used to be RSLogix500 Lite that could be Downloaded for free to Program some of them, but I am not sure if it is still available.

Stu....

I am looking at 120VAC outputs and 120VAC line power as this will have to be mobile.

Any sugestions on Allen Bradley plc's? We get good discounts on Allen Bradley stuff through a supplier at work as we run their contactors and relays in all out cranes we build

This application sounds like a good fit for a sequencer or drum stepper. Is it safe to assume that the sequence is timed?

And if it is for home/hobby use, note that the programming software will cost quite a bit unless you use a Micrologix 1000 or 1100 which are supported by Micro Starter Lite. That version of RSLogix 500 can be had for free.

With a "Drum" or "Sequencer", you can basically fill in a chart with "1" where you want valves to turn on, and "0" where you want it off. Each row would have 5 randomly chosen "1"s in it and the rest zero.

You can fill in the data by hand or programmatically.

You can even use some external program to randomly generate the sequence and then import it.

When you run it, each time the sequence or drum advances, it writes the next row of data to the outputs. This makes for a very short and sweet program that could have literally thousands of steps. If you want the pattern to be less predictable, just make the sequence long as possible (it's only data, no extra logic), and perhaps pick a pseudo random starting point, or even a pseudo-random step each time it advances.

Or use PLC logic to alter or shuffle the rows periodically.

I also recommend isolation relays between the PLC outputs and the solenoids so that if one of the solenoids goes bad, it is an easy fix.

Another fit for this would be a Click PLC by automation direct. It is very inexpensive and the free software has a sequencer type of instruction too.

Does your design call for input to tell the PLC when a target has been hit? How about "keeping score"?

No it does not call for an imput to tell when a target has been hit. It will be for archery shooters. At the end of each sequence we will go down and score the arrows and pull them out of the target then do it all over again

nv02cummins said:

Ok cool. I have talked to a couple people that have systems like the one I am looking to build but they wont give out any info as far as plc stuff goes so thats why I am on here.

I have been doing some looking around at plc's and there's so many options is overwhelming. What are some plc's to look at? I have been told to look at the Click plc's at automation direct. Would that be a viable option for this project?

Click to expand...

As a matter of fact, some time ago there was a thread on the Automation Direct forum started by a soldier who was developing a similar system for a firing range, using a Click PLC. I've worked with the Click and agree that it would be a good choice for your project.

One thing you might want to consider is the choice of air versus electric actuators for the targets. If the system is going to be permanently installed, it might not make much difference, but if it's going to be moved on occasion, you may find that cables are easier to manage than air lines, and you won't need a compressor.

I thought of this Automation Direct series of videos when I read your description of what you want to do.

http://library.automationdirect.com/diy-halloween-pneumatic-props/