what plc is the best?

can anyone tell me what plc is the most user friendly?

I'm chewing a hole in my tongue!

microthene sent this to me, via Private Message...

microthene wrote on Today 04:50 PM:
why are you chewing a hole in your tounge?
do you what plc is the most user friendly?
i just started using plcs, the only one i have used is ge fanuc
but i have a couple of mitsubishis laying around the shop not in use. i didnt want to buy software for them if they where dificult to program.

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To which I said...

I will post my response On-Board. Please continue to do the same.


My response...

My FAVORITE PLC is Texas Instruments. They have been bought out by Siemens. There are a couple of other PLC's that use the same programming philosophy. I've worked with over a dozen PLC's in my experience, but the TI is the most Human-Like!

The question you raise is a PI$$ING CONTEST between us Regulars.

This question has been raised every now-and-then since this site was created. It boils down to a... "My Dad can beat-up your Dad" kinda thing.

The first PLC I learned was Allen-Bradley. Since then, I've come to KNOW (I wish I could underline "KNOW" several times!) that the only people that LOVE A-B haven't seriously tried anything else!

In terms of your "easiest" requirement, the closest solution I have is for you to buy a Siemens S-7 (2XX). They were actually designed by TI and have the TI Programming Philosophy - Human Like!

Alternatively, try Data Control. (Is that the right name, TOM?)

Microthene,

The only person who can answer your question is you. A PLC that is to me, the epitome of user friendliness may be the most obscure, incomprehensible, POS to you.

Some brands of PLC offer inexpensive or free trial versions of their software. Find out what's available and take it for a test drive.

Which is the most user Friendly

Well I have a personal favorite...but the real answer to your question is the one that you understand the best. This is usually the first brand that you were able to write a good program with.

After your are comfortable with your first brand you will compare all others to that one. "Well I'm used to working with Brand X. And every time I use Brand Y I have to remember that I can't use a timer like that."

That is the closest thing to a un-biased answer as I think you will get...

Terry, that was admirable. Your succinctness serves your point well.

Actually

Yes, the S7-200 was designed in the US. TI had long since sold its PLC division when the S7-200 was designed. Perhaps some of the old TI programmers helped with the S7-200. The old S7-200 MicroDos definitely looks like the older TISsoft.

I like the S7-200. It has an excellent instruction set, but it doesn't have the MicroLogix MSG block. Therefore it doesn't communicate well with our products. If Siemens would only make a S7-200 that can be a Profibus DP master I would bump this guy to the top of my list.

The S7-300 can be very powerful in the hands of a real programmer. One must learn how to program in STL (assembly language) to get the most out of S7-300s. Therefore the learning curve can be long and steep.

AB's instruction set is not as nice as Siemens, but it has a pretty consistent, flexible and powerful communication system. This makes it my choice if one needs to do a lot of communications. ( One needs to do a lot of communications to work with our product ).

The old Modicon 984 instruction set was the most awkward instruction set ever. I have heard of love/hate feelings from my customers about the new programming package called Concept. I have not had the time to evaluate it. Modbus Plus is the first and still one of the best field buses. Rockwell's producer/consumer model is just an improved version of the Modbus Plus's Global I/O. Modbus TCP is popular only because it is simple to implement and requires few resources. Rockwell's Ethernet/IP is far superior, but it requires a lot of memory, processing power and programming to make it work. Modicon MSTR block is roughly the same as AB MSG block but not quite as good.

Automation Direct offers an excellent bang for the buck. It has a TX and RX block that make communications consistent whether communicating over Ethernet or Modbus. Automation Direct's abilty to be a Modbus master very nice. Automation Directs Ethernet is also be fast and inexpensive. What I don't like about Automation Direct is it uses octal numbers for address, hex number in some places and decimal in others. Keeping all the straight requires mental energy that should be devoted to the application. Automation Directs stage programming is a big plus if your application requires a state machine.

Mitsubishi has a powerful instuctions set and are very fast. It does not have very good communications capabilties. I have not had the chance to try CCLINK. There is nothing like AB message block in the FX. It takes about 15 to 20 rungs to almost duplicate AB message blocks. The A and Q series screwed up their Profibus DP masters. They don't send the bytes over in the right order which causes us grief.

Omron is the king if you like one shots. Almost any instruction can be executed on a rising or falling edge. Its IDE is below average but the Omron has a simple but effective protocol called FINS which can be used over serial or Ethenet. Omron Ethernet is not real fast.

In the end I would choose Automation Direct for small projects and Control Logix for big project. Both of these processor have a pretty good IDE and excellent communication capabilies.

I admit, I am biased toward PLCs that communicate and work easily with our product. A few years back I thought speed/performance was everything. I have since learned that ease of use is most important.

Excellent Peter, but you forgot my favourite.....

but i have a couple of mitsubishis laying around the shop not in use. i didnt want to buy software for them if they where dificult to program.

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The basics of Mitsubishi programing is not difficult. It is the most electrician friendly programming software I have seen.

The timers and counters are programmed exactly as you would hard wire them in a panel (A supply and volt free contacts N/o N/c)

If you print the logic and turn it sideways it looks like an ordinary schematic diagram.

Then when you are more confident, it has a powerful set of instructions to keep learning

"Alternatively, try Data Control. (Is that the right name, TOM?)"

No.

(My tounge is bleeding! Get me a water proof bandage, please.)

Hello!
There are only two PLC:s that is worth to learn Siemens or AB.
Of course there are others manufacturers but you can't compare them to the big ones. I prefer Siemens because I've always used it and the new S7 family has such a good programming interface and the range of CPU:s and other things can't be beaten.

In europe we use siemens 90 % and AB 10%.
In the project's I know of in US, is 40 % siemens and 60 % AB.

I'm just talking about PLC:s not the big systems like honeywell etc.

The AB was propably created for the normal electrician to make relay connections. That's why you have to use ladderlogic to program the system.

Conclusion:

SIEMENS RULES !!


peter said:
The S7-300 can be very powerful in the hands of a real programmer. One must learn how to program in STL (assembly language) to get the most out of S7-300s. Therefore the learning curve can be long and steep.

I think you should get familier with the siemens STEP 7 programs, before you make such a statement !
You can program using, STL,FBD,LAD,SCL....+ A few graphical languages.. and so on. ALL Commands can be used in eg. Ladder

I don't think anyone can answer that question. People can relate their experiences, that is all.

Looking at myself, I am an OEM. My needs are very different that someone who is working in a maintenance/support position. I mainly look for ease of integration with other products, especially on the develpment software end. (e.g. Can I pass my tags/ descriptions from the PLC to the HMI software easily?) Also, ease of re-using code. These could be quite different form another's desires.

Also, though I have experience with 5-6 different PLC's, some of that was quite a while ago. I used to use a lot of Mitsubishi, but I haven't touched one in over five years. How can I really give advice?

There are quite a few new products out there, and they are experiencing growing pains but have great potiential (e.g. Controllogix, Concept). So, not only would an asnwer to your question be difficult, it would also be transient.

I prefer Siemens because I've always used it

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There's a story that's popular in my neck of the woods. An old farmer, with a reputation for being something of a 'character' was being interviewd by the local media as he left the polling place on election day.

Interviewer: "So tell us Mr. Jones. Whom did you vote for?"

Farmer Jones: "I voted the straight Republican ticket."

Interviewer: "Why did you vote for all the Republicans?"

Farmer Jones: "Because I'm a registered Republican.

Interviewer: "Why are you a Republican?"

Farmer Jones: "Because my father was a Republican, and his father was a Repblican. As far back as I can remember, everybody in my family has been a Republican."

Interviewer: "Well, don't you think that's a poor reason to choose whom to vote for? Suppose your father had been a horse thief?"

Farmer Jones thinks for a moment, scratches his chin, finally says, "Ya know sonny, I see your point. If my father was a horse thief, I guess I'd be a Democrat."

I take it the pi$$ing contest has now been officially started?

Seems to me before you could quantitatively state that any brand is the best you must know all brands and all circumstances they are used in. Any way you look at it a PLC is just a device that is used in automation process just like many others, there will always be choices based on cost, personal experience, training, familiarity etc.

Everyone has a preference based on certain factors but what may be the best for one person/company/application may not be for another.

Cool to see someone else get slammed on the subject.