Comments on PLC Vendors.


Thread Starter

Rodney H. Park

I am co-sponsoring a team which has been evaluating various vendors of complete SCADA packages (hardware and software) for a chemical research environment. The team has compiled a list of requirements based on our user's needs. This "requirements" doc has in turn generated a short list of vendors. The team will be spending some time in a "hands-on" evaluation creating a test configuration to confirm or deny some of the vendors claims. We are also developing a decision matrix to move the teams decision to a final decision as there are more aspect of the decision than strictly technical.

I have confidence in the teams technical evaluation but am looking for comments (pro and con) of the following vendors (GE-Fanuc, Modicon,
Honeywell, and Siemens). How easy is it to work with these firms? Has anyone experienced any "gotcha's"? Are there any issues which would be helpful to know about? Does anyone have any "war stories" that would be helpful to know now before a decision is made. These are not the only questions of interest but the only ones that come to mind now.

We are currently using many Honeywell S9100e controllers with either Scan or Plantscape as the HMI.


Rodney H. Park
Automation Group Leader Riverside
(708) 442-3737

Open ended questions, all you will get is personal preferences.

I note that AB is not shown, but frankly, why would bother with anyone other than AB or Modicon. In terms of installed base, availability of experienced resources (staff or integrators), & application experience, they have it hands down an all others.

Regards, ray pike
Preference to fixed hardware not withstanding

I have found bus and need for both real time status and report status the most criticial. The use of open architecture and software in the begining saves money and time as you refine and change process in the future.
There are many good products out there and all responses will indicate somewhat of a personal preference.
If you require an accurate time stamp of data, I recommend the Siemens S7400 PLC. It is capable of easily incorporating a Sattelite Clock into the PLC and pass the time stamp to their HMI (WinCC) for data archiving. WinCC uses ANSI C for scripting.
If installed base is your only concern, use Allen-Bradley PLC's and Wonderware or RSView. I don't know if Wonderware still uses proprietary scripting still, but RSView uses VBA.
Modicon Quantum PLC's and Intellution Fix Dynamics work well also. Fix uses VBA for scripting.
I personally like Modicon PLC's for their programming software and RSView because of VBA, large library and ease of use.
I have worked for Allen-Bradley, Modicon and Siemens.

Hevelton Araujo

AB and Modicon probably "have it hands down on all others" considering the US; but worldwide, i believe Siemens can definately make a run for it.

Hevelton Araujo Junior
Gerência de Engenharia
Tel.: +55-31-34275852
Fax.: +55-31-34912077
[email protected]
Modicon in top 2 for SCADA? Is this US or worldwide? I must have been mislead as I didn't know they were even top 5.

I find that installed base is only important to the point that you can readily find people with experience with a technology. MS tries to make
the installed basesupport case against Linux but it just isn't the #1 factor in a decision. We use Omron PLCs at Honda, and have legitamate
problems with that, but I find AB far less responsive to customer concerns. Others are gaining share because they are more innovative and
customer focused.

Honda ELP/EQ staff

This is my first response to the list so I'll briefly introduce myself. I work for Honda of America Mfg at their East Liberty Ohio Civic factory in the Assembly Dept. We are far more automated than we ought to be, but it gives me nice exposure to a diversity of technologies. I'm not formally an engineer (dropped out of U of Illinois eng) but was brought into the
engineering group 3.5 years ago after they saw what I could do as a Maint Tech. Worked as an Eng Tech for a year or so before Honda at a Plastic Blowmolding plant. Was a Reactor Operator/Elect Tech in the Navy, Take my input from that frame of ref. The last few years have gotten me into VB programming enough to detest Microsoft and now I'm trying to pickup Linux
as I think it's a revolution just gaining attention. The LPLC project is what lead me here. Enough about me.

Our Dept sort of had RSView forced on us, but in our own evaluaton of SCADA from Intellution, Wonderware, GE Cimplicity, and Rockwell/RSView, GE and Rockwell were neck and neck at the finish line. This was only after heavy price pressure on Rockwell though. GE came in far more aggressive to get our business and meet our needs. Our Weld Depts at both Marysville and
East Liberty chose GE-Cimplicity and are happy with it. The only gotcha they mentioned was really just an oversight. GE neglected to include the cost of SQL Server client licenses in their quote.

I wish I could have used GE for a few reasons. First of all, from a price/performance perspective, the harware software bundle GE offered was a great deal. RSView only supports OPC and DDE to communicate with Non-AB
products. They pretend they are dedicated to serving users of other PLC's and make a big deal out of their commitment to OPC and that they hired the Pres of the OPC foundation. Our Weld dept is using Modbus from within Cimplicity rather than relying on a 3rd party driver, and they're very fortunate that they can. Our 12 year old PLC's don't speak it though. As for the rest, I can't comment.


Ranjan Acharya

Not just the vendor reputation or the market share, but the target application / industry must be considered in choosing PLC vendors and SCADA
vendors. A particular vendor may have a low or even negligible overall market share but be a leader in the field, of say, pipe lines or
pharmaceutical or automobile manufacturing.

In my experience all the vendors have one problem or another. There is no efficient yardstick to see which vendor is the best.

This answer is not much help, but I truly do not believe that "in the grand scheme of things" you can paint one major PLC/SCADA vendor as being poorer than another. For example, a good local systems integrator can hide the end user from shoddy products issued by any vendor. Also, a good vendors products can easily be messed up with sloppy implementation.

You should also consider PLC and SCADA vendors individually -- some independent SCADA vendors (Wonderware and CiTect, for example) work just
fine with a variety of PLCs and may assist you by not tying you down to one particular PLC or another. Some of the integrated packages out there are just a collection of individual packages -- just try to use them -- you will
clearly see the results of two (or more) independent teams of engineers and programmers "integrated" into one package.


Park, Rodney

Modicon scored in the top 3 based on our requirements document and is not based on any sales or market figures.
Yes, the questions are open ended. Our requirements document will drive a technical decision. We have all seen that the vendor promises are not always what they seem to be. I am looking for any and all information from those
who have knowledge of these systems including personal preferences. Personal preferences are usually based on some experience (but not always).

AB did not make our short list based off our requirements.