Siemens vs. Ab

Mike Williams

Member
Join Date
Jul 2002
Location
Alabama
Posts
222
From drives to software to plc, who is the best? Some people say "well I learned on ab so thats what i know". But the way I see it, if you have used some of the major brands, (and understand code)
you will choose siemens everytime, Right?
 
Please- not this one again.
This is old.

They are both great. Call your distributors- go see demo's- then
you decide.
 
Which Is Best?

Well, I think that it is somewhat like saying, "Who is the best, Micheal Jordan or Dan Marino?" Both are/were great at their own sports and some PLC brands are better for certain applications. I learned on AB and prefer the platform, but have found that AB presents some problems when it comes to networking and other brands such as Modicon with it's odd scan presents it's own problems.
 
Thanx wilwil67 for an educated response. I have worked with both a great deal an agree that both are very good. Your post is right on.
 
Your list isn't inclusive enough. Neither of the brands you mentioned is my favorite for drives, or for PLCs.

Over the years I have used a lot of different brands in a lot of different applications. I have my favorites, but I'm not rabid about them. (I like Cutler Hammer drives best, I like Automation Direct PLCs best, I like Exor operator interfaces best, I like GE pilot lights best, I like Turk relays best, I like ........) It has been my experience that a number of brands will do a good job, and if you put in a little effort and apply sound engineering practices you can work around the quirks of almost any brand. Every brand, including my favorites, has weaknesses and shortcomings, and everything made by the hand of man has problems.

I haven't been shy about A-B rants, but there are many things I do like about them, and I have had many successful projects using A-B products. Sometimes they make me very angry, but sometimes my favorites make me angry too.

It is "mom and apple pie" but none-the-less true that you have to evaluate each project based on the requirements and pick your brand accordingly. And the distributor/representative can make or break you on a specific brand. I have sound technical reasons for preferring Cutler Hammer VFDs, but in all honesty I use them by preference because I get great support and have good relationships with both the local dostributor and the factory applications people. That influences my decision at least as much as the technical evaluation.
 
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Mike, your post was obvious baiting, and I didn't want to rise to it. This will be the end of my participation in this discussion, as I have real troubleshooting, coding, and protocol analysis to do tonight.

There are two reasons that I don't like Siemens. My reasons are simple, they are personal, and they make at least as much sense as your boosterism.

They are 1914 and 1939.
 
Ya gotta know, with respect only to Rick's first sentence, Rick hasn't been keeping up on his meds. I too slip on mine once in a while. So, what else is new?

My personal opinion DOES NOT support Siemens, per se. But rather, the company that Siemens bought out (At least, the PLC division that they bought out), that is TI (Texas Instruments). TI decided at the git-go, to make the interface, between operator and processor, in favor of the human element - namely, you and me.

Siemens DOES NOT DO SO!

The S7-200 series is a TI product, while the S7-300 & S7-400 is OBVIOUSLY a Siemens product.

The difference in programming philosophy is GLARING!


Then WilWil67 responds and Mike says... "Right answer". So Mike, what the hell are you doing? Chumming?

Tom came up with the right answer, as far as I'm concerned. None of those product manufacturers out there produce the best products over-all. I certainly can say that AB makes a terrible drive!

Each, for whatever reason, has stumbled onto a good design for one product or another. AB makes a very good, albeit, unreasonably expensive push button. I have come to appreciate GE PB's more!

It's up to the designer to pick and choose carefully!

Finally, Ken makes an interesting point. A point that is real enough that I'll have to ponder it for a while. I can't, and will not, simply discard his point based on politcal correctness.
 
I am almost at the end of a Siemens S7-400, "Simatic", small job commissioning.

I am still amazed at my frustration with the plc/programmnig software.

Heare are a few "points".
1) Unless you know what OB's mean, (and which ones to load), then loss of power (trips) on any profibus drop will kill your PLC. Not nice if your cause it by turning off a circuit braker. Took a while to figure that - & how to fox it .

2) You use FB's to program with linked DB's. If you add new variables to FB's, better update the associated DB, & then remember to load both into the PC.
(You just don't have this mucking around in AB.)

3) Should you add variables (inserted) in a FB, then all bit mapping changes. Thus if another FB is calling your current variables, it will call a wrong reference. - your code is effectively corrupted, "big time". MAJOR flaw.

4) Limited number of timers.! Try using IEC timers instead, unlimited. But try pausing a timer - It will timeout in background, so when you release, it moves to "timout state". So if you need to use timers, better to use counters of 1 sec pulses instead.

etc.. etc..

Siemens software will let you, the programmer stuff up - even if you do not intend to. It's not robust enough for my liking. You do want the software to guide you & to prevent you from making silly mistakes.
I mean, if you the programmer is trying to minimise effects of operator mistakes, with your "robust code", why shouldn't PLCs/associated softwares do the same?

OK, once you "learned" the traps, you're an expert that can avoid them, but for a 1st user, frustrating.
 
unfortunately we use quite a bit of Siemens PLC's and drives etc. I can't say that I dislike them, but when we come across a problem, either programming or hardware then the odd profanity towards 1914 and 1939 does get mentioned.

To qoute Basil Fawlty "Don't mention the war, I mentioned it once and I think I got away with it!"

Appologies to any one who is not from the UK as you may not understand the above qoute, unless Fawlty Towers has been shown on American TV
 
Rick Densing said:


Then why did you ask the question?
Just getting the blood flowing. It worked on you, eh?
I was just putting a topic in to discuss. I find it interesting to hear what everyone else is using. I have used AD and they do have a good product. I like all the brands, hell, thats how we make our living. I guess in the future I should just sit back and read posts and leave all the answers to you "professionals".
 
You still don't get it, do you?

My first line was meant to illustrate that there is really no answer to your question except personal preference. Excuse me for trying to be a little creative.
 
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