Need to Setup a PLC Lab

  • Thread starter Mariano Lizarraga
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Mariano Lizarraga

Hello All,

I am EE Masters student currently enrolled in the US doing the control systems "track". I am working with a professor to set up a very small lab to start learning PLCs, the intention is that this becomes in the near future the base for a course in Real-time and Embedded computing for EE students; for PC platforms we are using Matlab and the Real Time Workshop with PC104 computers, and that is already working fine, but, the truth is that neither the professor nor I have any experience at all in PLCs (and of course Ladder Logic Programming) so I was wondering if any of you could post a link or give any suggestions of what would be a good setup for academic purposes, we have around 1500 dollars to spend and we would like to take as much advantage of it as possible.



Bob Waterfield


It is going to cost you a little more than $1500 to do all that you want to do. Allen Bradley has a small PLC, the SLC500 that would be right up your alley.

If I were starting a PLC project I would want the "rack" (AB has a 7 slot rack), processor/power supply, analog input card, analog output card, digital input card and digital output card. With this as a minimum, you can program your ladder logic with physical inputs and outputs that the student can see in the "real world".

Also the GE Fanuc 90-30 is a nice unit that can be configured in much the same way.

Now when you really want to get fancy and get a full lab going (future and lots of dollars), the Siemens S7 PLC with profibus network would be the way to go.

Speaking of spending money, did I say that you will have to purchase the programming software in addition to the hardware. The companies get you coming and going.

Hope that this helps you get started.

Bob Waterfield
Nucor Steel Berkley SC
[email protected]
I would have to suggest using an Allen Bradly SLC 50 PLC, they are cheap, you will find them in most applications and they are easy to program.
I would definately consider the Omron CJ1. It has the very latest and fastest processors, huge function list, including autotune PID, is far cheaper than the other suggestions and is extremely small, I/O cards are not much bigger than a cigarette packet.
The software is also excellent with programmable function keys. You programme it to work the way you want it to work.
Motion control, Device Net, Ethernet, Modbus and other protocols are available. No rack required, just mount to a DIN rail. Up to 2560 I/O.

Try this link for a leaflet
I would suggest the Automation Direct line of PLCs. They can be purchased over the internet at Something like the DL205 series, with their 7-slot chassis. The automation direct equipment is much cheaper than the big name PLCs. Their customer service is excellent; you can order on the internet and have it the next day via FedEx. In addition, they are more 'open' than most, supplying documentation, cable schematics, and protocol manuals online for free. Their programming software is cheap and excellent. They have a huge selection of modules that cover everything including supporting tons of protocols from other companies.

Anybody else have any comments on them pro or con?



Try contacting the nearest representatives of the PLC companies that are strong in your area, and ask what they can do to help you. As a Rockwell
distributor, I regularly assist colleges and trade schools in setting up PLC labs. Rockwell has a program specifically to encourage projects like yours, and I expect the other PLC companies do as well.

Hope this helps!

Larry Lawver
Rexel / Central Florida

Michael Griffin

I would suggest that you talk to the local reps for AB, Siemens, Omron, etc. and discuss what you want to do. They will sometimes donate hardware and software for this purpose (at least they have done so before in my country). Your 1500 dollars won't go very far if you have to buy everything.

Michael Griffin
London, Ont. Canada
If you want to train people on basics of PLC within your budget, automation direct is probably where you will end up. Their stuff is 50% cheaper than Allen Bradley, as they advertise. Programming software is good, for a basic PLC controller.

If you want to train people on what they will actually be using on the job, then pay for the Allen Bradley PLC's. You don't have to get the SLC 500 series as their Micrologix controller programs the same way for less money.

Note: The school here got a really good deal from A/B on their hardware, and even better on the software. Since you use what you learn first, and what you know best, the manufacturers are more aggressive to give free hardware or really good deals out.

Also try out ebay for used stuff. It should be good compromise for the money you are spending. Possibly ask sellors if they can donate and write off hardware cost.
It has been a while since I have been actively researching this, but some thoughts:

To learn Ladder Logic (in fact, all IEC 61131-1 languages) Modicon Concept has a development environment complete with PLC emulator at no charge.

Automation Direct has very inexpensive PLC's.

There's an open-source embedded-PC PLC project at
which might be of interest.

Labview is an interesting product as well:
The main product would knock out your budget, but there's an eval package
plus you might contact NI directly about an academic deal..


Rufus V. Smith
Software (esp. Automation) Generalist
Recently Unemployed and available
Contact at: [email protected]

Curt Wuollet

This is a place the the Micrologix 1000 and 10 point RSLogix deal might be good. $100.00 for the PLC, $50.00 for a cable, download the software for free. Provided you have a current Windows computer around, that would leave you with cash for pushbuttons, lights and other periphrals to do things with. It's a big step from here to even entry level "regular" packages.


Friedrich Haase

Moin Mr. Lizarraga,
moin all,

Just to learn how the average PLCs work you don't require a real PLC. You can use your PC/104 computers and a PC-based PLC software.

A free, non-commercial PLC you can find at

For educational purposes this is the cheapest solution. And you need not bother about the nifty details of a specific PLC brand.

Friedrich Haase
If you want to learn the basics of ladder logic, why not start with the FREE DCIPLC software. This program runs on a PC and allows you to write and test ladder programs without any hardware. But if you do want to control stuff, DCIPLC can do this too. DCIPLC can communicate to up to 4 DCI-RO16 8-channel relay/opto boards via RS232, giving a total channel count of 32 relays and 32 opto inputs. There is also a HMI program that links to DCIPLC so that you can design an operator interface, with ledgends that change state in line with the I/O. see for more information
Check out They offer PLC simulation and programming software for education. The software emulates AB plcs, which are by far the most common and most likely to be encountered by in the real world. If you want to consider a real PLC then consider the AB Micrologix line. They have some small bricks that can be had for less than $200 each, but have the same intruction set and functionality of bigger PLCs. Also contact your local AB rep about educational partnerships because Rockwell software for programming your PLCs can be very expensive.

Donald Pittendrigh

Hi All

Siemens also has some special offers on multiple training licences and starter kits from time to time, well worth your time to give them a call. I have also heard the comment made that if you can work a Siemens PLC you can work any PLC, this may or may not be true, but for what its worth!!!

I would not use PLC direct, I am not 100% sure but I have an idea their stuff is not quite IEC1131 compatible, and although I like their
approach to programming logic using Visio, it may well be appropriate to deal with the mundane before the exotic.

I would suggest taking a look at Wonderware In Trak which is acclaimed to be IEC1131, and I do have some very good reports of InTrak plants in
my area. The soft PLC route is a good one as the hardware cost is often the killer. Wonderware would possibly be open to a promotional deal for
training purposes, they are a large financially competent company with a modern sales policy, in fact probably the market leaders in this regard.

Donald P

Bruce Durdle

I've been lurking on this one for a while, but feel it's time to add my $0.04. (the $NZ is worth 50c US).

So far the discussion has been focussing on teaching programming. That's fine, but that is only about 25% or less of the requirement. Many of the fine details of a real PLC application come when we have to tie the operation of the program into the constraints of the real world.

As an example, we recently had a discussion here on the requirements for a program to drive a reversing motor system. No-one anywhere in the
discussion mentioned the need to have a delay between turniing the A-B motor off and energising the B-A direction. Yet, without such a delay
somewhere, smoke and expensive noises can be expected. There is also a need to cover for the case where the motor is tripped by an electrical fault outside the scope of the PLC, and also E-stops need to be considered. These are fundamental requirements for a real-world PLC applications, and students should be exposed to these problems, and the need to cater for them, from a very early stage.

Developing a PLC application (along with most other control system applications, but probably more so because of the low-level nature of the
basic functions available) places a very large requirement on the practitioner to make sure the task is fully specified (including things like motor switching delay times which will probably not be mentioned in a user-prepared Requirements Specification). The Requirements Specification
must be completed by making sure all the fault cases are accounted for, operational needs are fully considered, and so on. It must then be turned into a Functional Spec or similar, taking into account the peculiarities of the chosen platform. Finally, the FS can be coded - this is at most 25% of the work. The program must be fully documented in accordance with the needs of those who will be maintaining the system in the future.

We do not do students any favours by pretending that PLC system development is simply a matter of sitting at the keyboard and entering code. That way lies a great heap of spaghetti, that will possibly work in the cases where it has been tested and tweaked to perform, but is essentially unpredictable outside that range. Simulaton is of some use, but the limitations of simulation must be fully understood.

A "PLC Lab" must have access to a number of real-world systems to be controlled. Ideally, students should be exposed to the properties of a range of I/O modules in a range of applications - the dreaded triac leakage problem is one that needs to be covered.

I would not use PLC direct, I am not 100% sure but I have an idea their
>stuff is not quite IEC1131 compatible, and although I like their
>approach to programming logic using Visio, it may well be appropriate to
>deal with the mundane before the exotic.

Yes, best way is to go straight to main PLC manufacturers original stuff.

If the lab is to be setup "for academical purposes", as stated by Mariano, I would suggest the evaluation of softPLCs, better if under GNU license and Linux operating system. There's nothing cheaper. It is also possible to buy something from micro-PLC manufacturers or
purchase some PLC simulators, but this last stuff unfortunately suffer of a lack of reality:
1. in automation world , micro-PLCs are mostly used only by a small part of integrators and mainly for a specific family of applications (e.g. packaging). Many of them do not allow online programming and have reduced fieldbus/networking/communication capabilities. Mastering one of these PLCs will not ensure one will be able to program other PLCs in a reasonably short time.
2. PLC software simulators often do not provide a complete instruction set and proper CPU behaviour. The editors are not the same you will use in the real world, so they're still useful for "academical purposes" but not for real training. The only simulators worth some money are those developed by main PLC brands themselves (e.g. Siemens, etc), where you use exactly the same tools (editor, Xreference,hardware configurator) and the identical instruction set you would use in the real world.

Just my opinions, eh :)

Luca Gallina