Need help choosing first PLC

Hello folks,

I would like to request your input and opinions to help me choose a PLC make/model for my company. I’m a manufacturing engineer with a mechanical / design / tooling background. I know next to nothing about PLC’s, instrumentation and process controls. So your opinions and experience would really help me out.

My company is a small commercial truck accessory manufacturer located in the southeast USA. I’m the only engineer here and there are no PLC’s in this facility. I would like to put some PLC’s to use for some small machine automation projects and for some automated product testing. I’m thinking that a PLC with 30 I/O would be more than enough for anything we would do here.

I would like to standardize on one brand, and even one model, if possible, to keep things simple. So I would like to solicit your opinions, viewpoints and biases on make/models that would be good for beginners from the following points of view:
* ease of programming
* durable / robust / trouble free use
* good value for the features, cost effective

The question I’m really asking is: if you had to start all over again in a small company with very basic automation needs, knowing what you know now, what make/model PLC would you choose?

Any and all opinions welcome and thanks very much for your input!

Nick

I would opt for the AutomationDirect DoMore 205 series.
I believe it will answer all three of your qualifications.
The full featured simulator is also great for a PLC beginner to learn the whats and whys for free.

You will get a lot of answers according to preffered personal choice like if you ask which car to buy but it mostly depend what you wanna do with the plc and operators operating the device. Because for a relativelly low cost, you can get a good plc from the good brand out there but the cost increase when you start looking at HMI to show what is the logic inside your program and process...
For a low cost device, PLC/HMI separate device from any brand won't compete against built in screen/i/o processor but you will get what you pay for.
If you want more reliability and not much from hmi representation, it is possible to figure it out at resonable cost using the basic hmi with the option of color ones...

I personnaly preffer Siemens because i really like their free technical assistance compared to other brand that charge you annually. The product quality is very nice too.

I think the Micrologix 1400 from Allen-Bradley is your best bet. Yes there are a lot of brands that may be cheaper up-front, but the big reason to use A-B is that you will have a much easier time finding people who know A-B than you will for any other brand. Whether you're calling someone in for troubleshooting or hiring someone, just about everybody in this field (especially where you're located) knows A-B.

The 1400 has 20 inputs and 12 outputs to start and is expandable to up to 8 add-on modules. It has built-in Ethernet/IP and is fairly low-cost. I see someone suggested Do-More, and while those might be cheaper, they are more difficult to program. Up-front cost is not everything.

Alternatively, for the smallest projects I'd go with a Micrologix 1100. It still has built-in Ethernet and can have 4 expansion modules but you're limited to 12 inputs and 6 outs on the base model. BIG upside though is that you can use the free version of RSLogix 500 on the 1100. I love the 1100 but prefer the 1400 because it has several "niceties" the 1100 doesn't have.

Don't bother with the Micro800 series. They are not true A-B products and are more trouble than they're worth.

Overall design, functionality, hardware and smart solutions I would pick Siemens, but I don't know how the support is in the States. You could use the Siemens LOGO, it's simple and cheap. You get a screen on the Hardware to edit timers, counters, values etc. If you wan't something more high end you could use s7-1200 with and HMI. The downside is that the programming software will cost you. We have used hundres of LOGOs and never had one broken.

We often use Siemens LOGO for cost effective automation tasks. The built in screen is the key here. But as I said the programing software for the LOGO has its limitations if you want some more advanced math.

This is my thoughts and I have only worked with A-B and Siemens, so my knowledge about other smaller brands are limited.

Using AB products because it is well known is a truth answer in USA if you aren't considering exporting. In the other hand you pay more for the same thing at first regardless of needing service or not. So if you save each time you buy 1, you may invest this to learn any other brand instead of being dependant. You also have to ask yourself if you want your system to be troubleshooted by anyone in USA or just by your specialists.

If you go with ML plc, make sure to filter and protect your power feeder as i experienced some failure with that entry level plc. Instead of the stupid general answer ''check your groundings'' i protected the 120v ac or i'm now mostly using 24vdc PLC version below a good 120/24vdc power supply that do all that and no more weekend call about a blown or memory lost plc

rQx said:

Overall design, functionality, hardware and smart solutions I would pick Siemens, but I don't know how the support is in the States. You could use the Siemens LOGO, it's simple and cheap. You get a screen on the Hardware to edit timers, counters, values etc. If you wan't something more high end you could use s7-1200 with and HMI. The downside is that the programming software will cost you. We have used hundres of LOGOs and never had one broken.

We often use Siemens LOGO for cost effective automation tasks. The built in screen is the key here. But as I said the programing software for the LOGO has its limitations if you want some more advanced math.

This is my thoughts and I have only worked with A-B and Siemens, so my knowledge about other smaller brands are limited.

Click to expand...

I use to call the LOGO a logic relay timer more than a plc because of it's limited function and at some points, the price of a 1200 without hmi could comes close for what it gives...But if you need to change data without a programming pc, the hmi price make it more expensive but trying to change manny parameter through a logo screen could be a PITA also VS a good HMI

NickA,
welcome to the forum.

since you are a mechanical Engineer i would suggest the following.

1 look for plc reps in the area. as already stated AB is the most used and also. what do they have in stock, how's their tech support.
2 see if anyone in the plant is familiar with plc's and the brand. they can be a great asset.
3 look for OEM's in the area. Machine builders, automation specialists.

regards,
james

Jeff23spl said:

I use to call the LOGO a logic relay timer more than a plc because of it's limited function and at some points, the price of a 1200 without hmi could comes close for what it gives...But if you need to change data without a programming pc, the hmi price make it more expensive but trying to change manny parameter through a logo screen could be a PITA also VS a good HMI

Click to expand...

Well that depends on what you are programming. To call it a logic relay timer is to simplify it, it can do very much. I think the limitation comes when you want to work with more math and using diffrent memory variables. Ofcoarse if you have to program a more complex machine or have more I/O then the LOGO has the LOGO isn't the best choice. But if you just want to as the topic owner said "like to put some PLC’s to use for some small machine automation projects and for some automated product testing".
That could well be done with a LOGO if it's not to complicated. The big bonus is that you can easy change variables. A logo in Sweden is about 140$. A s7-1200 with a small HMI is maybe 5-800$ depending on the HMI. You can't neglect the fact that the LOGO is also mush more simple to handle and for a beginner it will be more of a quick start.

So it all comes down to what task and how advanced it is.

It depends on multiple factors: what is your programming background... in my case (and this probably is too overkill for what you mention) I chose Beckhoff, as they are using different PLC levels, and with the same (and free) software you can program all of them from the smallest one to the more powerful one (a PC) and all from an Ethernet cable and a normal computer.
Free amount of IO available, plenty of fieldbusses...
Now that you have to choose, don't limit yourself, take a look at their products and decide later.

Good luck!

Depends on what you wish to automate. Do you need analog? Do you need temperature control? Do you need a HMI? I generally find that starting out at the bottom end means that you find more and more you can and wish to do. Then you find you have run out of grunt and have to change to something more powerful that can do a lot more anyway.

Nick,

Welcome to the forum. You picked the right place to ask your questions.

Based on what you have conveyed, a simple product with versatility, yet powerful and in the small end of I/O requirements will suffice.

There are many PLC manufacturers that offer products that meet the requirements you have stated, however, let me offer up a product line from a company called Triangle Research. They manufacturer an Ethernet enabled embedded PLC. Based on your I/O request of 30 points, the FMD-1616-10 will more than meet this required, and then some. In addition to the digital I/O there is analog and Ethernet. This product is also expandable should you require more I/O.

Should you decide to proceed with this product, you will want to purchase the starter kit first, which includes one controller, software and applicable hardware for programming. The starter kit price is $365.00. The individual unit price for recurring purchases is $295.00.

More information can be found through the following link:

http://www.eternity-sales.com/tri-plc/fmdseries.htm

Manuals are available through the link provided above. Triangle Research offers some good support for their product should you have additional programming questions. We can also develop programs (for a fee) should you decide to go that route. There will be a learning curve for any PLC product you choose, in that you are not currently familiar with this type of product. We will be able to assist you along the way, as needed.

Should you have any questions, feel free to post, pm or email me through the link below.

I would go with Allen-Bradley also, like FactoryTalktotheHand said.
The ML 1100 for a small proyect, the ML 1400 for a bigger proyect.
With AB there are a lot of people (in the US) that can help you, and if its your first proyect that is something very important.

Many thanks to everyone who responded, I greatly appreciate your input and wisdom. I’m going to research your suggestions and I’ll print out this thread and save it for future ref. I never gave any thought to HMI’s but that could be a useful feature down the road. The rationale for AB is sound too. Starting out too small could hamstring us in the future, but I do have to sell management on all of this, and it would be easier to do that starting out small and low-cost. So there’s that same old balancing act that we all contend with.

Thanks again to all; I can see that this web site and forum will be most helpful to us as we move forward

Best regards,

Nick

NickA: Maybe is not what your requesting but this book will drive you into plc world:
http://forums.mrplc.com/index.php?autocom=downloads&showfile=156
It's free.