I am setting up a test system to train my office mates on the basics of PLC-based control systems.

I plan to use a few basic I/O (at least 1 AI, 1 AO, a few DI, and a few DO) and some well-known HMI software. I'll use some laboratory equipment to make a "beverage distribution system." The entire system will sit on a spare desk in the office.

I need to select the PLC (and programming software), I/O hardware, devices, and HMI software, and the communication hardware I'll need to connect the PC to the PLC.

In my business (pharmaceutical and biotech), I see a lot of Allen Bradley and Siemens PLCs.

I was looking at the Siemens 224XP because it has all 4 types of I/O onboard. While looking for a PLC price comparison, I came across control.com.

So I decided to sign up and describe what I'm doing. I'd be happy see if any of you have opinions about hardware/software selection for the purpose I have described.

 

If you just want to teach the "basics", then I wouldn't worry too much about analogue I/O unless you have something specific in mind which can make use of it (e.g. a PID process). People can learn all of the "basics" without using any analogue.

I have seen people set up training systems that used a potentiometer input and a voltmeter output, but those features never saw any use. At the "basics" level people are trying to learn about how a PLC scans, what a rung of ladder is, what a timer or counter is, and other things like that. All of that can be done with digital I/O.

What usually matters more is whether the programming software is free (or very cheap) so that everyone can get their own copy. People will be spending more time in front of the programming software while they are trying to come to grips with the basic concepts than they will be testing the program on the PLC. If the software is free, then they can also load a copy on their PCs at home to play around with it in the evenings.

If everyone has to share a single copy of the software then it becomes such a headache that a lot of the people won't bother doing anything with it. From your description it appears that people will be expecting to pursue this in their "spare time", so you want to lower the barriers to their participation as much as possible.

Have a look to see what you can get in terms of free or very cheap versions. I know that the software for Koyo's newest PLC is a free download. Some of the other smaller vendors may do the same. Some of the larger vendors may have crippled versions that only allow small programs (e.g. a few dozen rungs). Those may be fine for your purposes as long as nobody needs to write a large program.

If on the other hand you want these people to be using the actual models of PLC which you have in your plant, then you will have a different set of considerations. If these PLCs are the larger AB or Siemens models though, then the hardware plus software might be beyond your budget.

However, I view "basics" as being what is common to all PLCs regardless of brand or model. Once you have to worry about brand or model specific features, then you are talking about "advanced" training.

 

I think I will be selecting an LS PLC (Master-K120). The price is low and the programming software is free.

I am still looking around for a SCADA software that will provide a decent overview of interface and data collection functions.

This system will be for tinkering and training. There is no risk to public safety, so please forgive my lack of awareness.

My thanks to anyone that can recommend a good software product that would allow me to demonstrate some features without spending a ton of money.

 

Why pick a relatively unknown PLC?  (I've never heard of it, anyways) 

I am pretty sure that A-B still has a free download for RSLogix500 that is limited to a 10 I/O Micrologix PLC.  I have seen plenty of gently used Micrologix on EBay for under 100 USD.  You can also find the prog cables on EBay.

 

Thanks for the responses. I should mention a couple of things....
I'm in Korea, thus the choice of the LS model.
As for analog inputs, there are 3 reasons.
1. The folks in the office need to become handy with I/O checks using a signal generator.
2. The data collection and alarm features of the SCADA will be a lot more interesting if we have at least one analog value.
3. My boss wants the training system to utilize a PID control loop.

The simplest thing I can think of is temperature control of a laboratory-type glass vessel. But I haven't found a heating/cooling device that will accept an analog output. I already ruled out a control valve to run hot or cold water through the jacket of the vessel because I won't have any plumbing at the desk.
I've been looking at beer making equipment and aquarium equipment, but it seems that most devices are on/off based on a thermostat, not true analog control.
Thanks again for showing interest in my little project.

 

in response to William Sturm:
That is a great tip on the micrologix PLC.
I had ruled out Siemens simply because the software is not appropriate for basic training.
I ruled out Allen-Bradley due to price.
RSLogix500 with less than 10 I/O would be perfect. Maybe I'll get lucky and find a similar deal for RSView? I'll look into it.

 

Have you looked at Unitronics?
Built-in HMI.
Free Software (download & use before buying PLC).
Very low cost.
Expandable.
Auto-tune PIDs.
High speed inputs for encoders.
PTO outputs.
Analog inputs and outputs.
Verstatile comms - Ethernet, Modbus, Canbus, & more.

Bruce A.

 

IMO, select what you already use in the plant. A small AB system such as a Micrologix 1100 has serial, ethernet, DI, DO, AI, an LCD screen, and costs not a whole lot (under $500 depending on your discount level). You can add an AO card for about $300. The software for the micros is not free, but can be had for about $500, IIRC.

As for an HMI, I would also stick to what you already use.

In fact, you might be able to borrow some stuff from your spare parts
stockpile and not end up spending anything.

 

For a demonstration PID application, consider using a water tank with a pump. I looked into this type of application for someone last year. The biggest problem though was that things like aquarium pumps tend to be AC which would mean constant speed (unless you can find a cheap variable frequency power supply).

However, have a look at the following. It's a miniature DC water pump for $10 that is intended for educational kits. I didn't end up buying one of these, so I don't know how controllable or linear the pump output is. However, it appears to be driven by a DC brush motor, so it would be variable speed.

http://www.kidwind.org/xcart/product.php?productid=24&cat=71&page=1#tabs

Parallax used to sell this as part of one of their education kits, but now it's sold by someone else (Parallax now just links to this from their web site). Parallax also sells cheap ultrasonic sensors that might be used as level sensors.

For a tank, a plastic jug (1 to 3 litre) would probably be best.

 

I know that Opto22 www.opto22.com has the exact type of training tools you are looking for in your office.

You can download a beverage filling simulator with limitless tags and install keys at:
http://www.opto22.com/site/pr_details.aspx?item=PACPROJECTBAS&qs=100510241045,,,1,3&

Opto 22 also provides an instructional video taking you through all the steps: installation, programming and debugging.
http://link.brightcove.com/services/link/bcpid1416062134/bctid1488623390

Opto 22 is used in filling systems all over the world for Coca-Cola, Pfizer, New Belgium Brewing, Cervezeria Nacional de Panama and many others. If you should have any questions feel free to email me directly. [email protected]

Cheers,
Rene

 

I'd like to suggest using Logixpro software for a good introductory course in PLC's. I've used it in my industrial PLC classes, and have had enthusiastic feedback from students. I usually introduce a topic using the Logixpro software before hands-on training with the PLC hardware. Logixpro can be downloaded from TheLearningPit.com on a 2 week trial basis, and it's about $40 per license to use.

Steve

 

TRy EZPLC. It has a PLC come touch screen and the I/O modules are very cheap, including the software. I programmed one for an engine room control panel and it worked great

 

You have to take a look into the FREE PAC CONTROLLER SIMULATOR included into the Opto22 's PAC Project Demo, it will let you build and run your control estrategies and then design and test your HMIs without any limitation and without having to expend a dollar.

You can download it directly from the site www.opto22.us, you will also find some instructional videos about how to start with the the PACs at www.optomizeonline.com/videos.html

Please feel free to contact me if you have any question, my email is germinal [at] optomizeonline.com

Enjoy it,
Germinal