Big News Inexpensive Ethernet in a PLC

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Thread Starter

Curt Wuollet

Hi all

A little while ago I had wondered out loud why a PLC with an Ethernet port was hundreds more when the hardware has to be less than $10.

I was searching for a way to get more comms, and I went to the Automation Direct website to see if there was a good way to add ports to a Click. I found that I can now get a Click PLC with an Ethernet port and ModbusTCP for an extra $20. Fantastic, I will follow with a review. There are so many possibilities for this, gateway, remote I/O, etc. etc.
 
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It's still a Click though, and they kinda suck (mostly the programming software), but at least it's one more option for getting some Modbus/TCP remote I/O for a good PLC.

(And not saying it's bad because it's from ADC -- Do-More's are just fine)
 
Not only is the hardware barely a few $$ more expensive, but it adds 1500v ground isolation! Given more and more simple control/gateway devices are using arm-32bit devices anyway, they clearly have both the horsepower and open-source TCP/IP stacks to make them effective.

In my opinion, the only value of RS-485 (NOT RS232) is that RS-485 allows many devices to be cheaply multi-dropped, where Ethernet still requires a port-by-port cost of tens or even hundreds of dollars per port.
 
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curt wuollet

> It's still a Click though, and they kinda suck (mostly the programming software).

That makes me curious about whose small PLC software doesn't suck in your opinion. You should try AB's software for their micro series:^).
I think that's a generational thing, or maybe a *nix thing. I much prefer a small programming package that does only that, loads in a second and takes you right to the ladder. The Click does everything I've needed in this business and it's fast and easy to maintain.
Oh, I forgot to mention that it now has online editing and according to AD, it's 3 to 10 times faster. The Ethernet only does ModbusTCP, but that's still a big step up. I've ordered a couple, one with RS485 and one without for a system I'm building. I'll review them once I see them work. I have more than 30 of the original running for more than a year now with zero problems. Programming them live from anyplace on the campus sounds great to me for certain situations.
 
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> That makes me curious about whose small PLC software doesn't suck in your
> opinion. You should try AB's software for their micro series:^).

Oh agreed, the Micro 800 stuff is completely dorky (although I do like the capability for user-defined functions in a low-cost PLC).

What do I like?

I like the current Siemens offering very much, and S7-1200s start in the $200 range.

The Do-More software is very good (written by Host and sold by ADC like the Clicks), and they're going to have a micro in about a year, and a nano after that.

RSLogix 500 programs some micros, and it's excellent.

DirectSoft for the original Koyo PLC's sold by ADC was quite serviceable, though there were some weak points.

I like the Omron's CX-One pretty well.

What else do I hate?

Idec, Delta, and Unitronics. All terrible. Dishonorable mention for most implementations of CoDeSys, though not bad enough to make the previous list.

> I think that's a generational thing, or maybe a *nix thing.

It can't be a generational thing unless you're a thousand; I'm as old as the hills and have been doing this stuff for 30 years or so.

> Oh, I forgot to mention that it now has online editing and according to AD,
> it's 3 to 10 times faster. The Ethernet only does ModbusTCP, but that's still
> a big step up. I've ordered a couple, one with RS485 and one without for a
> system I'm building.

I agree that's major. I'd probably be willing to use one as remote I/O for a good PLC (especially if I don't have to put in a little stub program).
 
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Russ Bartels

In most cases we are paying for more than just the Ethernet chips but also for a more robust processor to handle Ethernet and more memory plus development of the next generation.

Also many of the "cheap" Ethernet ports are actually embedded Serial-to-Ethernet adapters.

Of course a little extra money for the manufacturer is nice too.

But do your home work.
 
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Curt Wuollet

That's interesting because my last experience with TIA Portal put it just a little higher than CCW. Too much putzing before you can look at the logic. And huge and slow.

And I think the Click software resembles RSLogix more than anything else. DirectSoft is OK except for the BCD and octal mickey mouse, andthat's coming from someone who programmed computers with octal op codes. RSLogix is pretty much the gold standard for getting right to work. I suppose they'll bundle that with crap to program everything I'm unlikely to ever see and ruin it too. The current trend for horribly bloated do it all packages makes me look forward to retirement. SoMachine didn't impress either. I suppose if all you do is commission new stuff, all in ones might be usable. But for maintenance or a quick look to see what sensor is broken on logic you didn't write, they are pretty close to useless. Especially if you have to support half a dozen brands and they mess with each other. I'd be interested in a Host Micro but the DoMore software seemed pretty convoluted, IMHO. For a while, packages were similar enough so that you could intuitively run a new one without much of a problem, but they are diverging again. I think the need to deal with several packages colors my opinion, as does the type of work I do. If you had an all (insert brand here) plant, life would be simpler, even with sub-optimal software.

Regards
cww
 
My experience with TIA Portal parallels yours. It is a huge package that's cumbersome for someone to use to get to the logic for troubleshooting. Their old Simatic Manager is better, but not nearly as simple/clean as RSLogix.

It's been a couple years or so since I messed with CCW and I was NOT impressed then. It would have made SO much sense to use the existing RSLogix framework for the Micro 800s. There could have been a free version of RSL5k just like they have a free version of RSL500 Micro.
 
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> That's interesting because my last experience with TIA Portal put it just
> a little higher than CCW. Too much putzing before you can look at the logic.
> And huge and slow.

Well, my split between development and online diagnosis is at least 60/40 tilted toward dev time, maybe more. If you're starting a new project, it takes a couple minutes to set up the PLC type and I/O and so on, but I tend to work on each project 50 times maybe, so the initial fire-up time isn't really in issue, unless it occurred for each session. The software (the PLC, really) has nice features. TIA is big, and it can be slow. They need to work on that, or at least keep it from getting any worse till the hardware catches up. TIA up through 11 was supposed to be pretty buggy too, but I wasn't using much Siemens in those days so can't comment.

>DirectSoft is OK except for the BCD and octal
>mickey mouse, andthat's coming from someone who programmed
>computers with octal op codes.

Yeah, that and poor online data views were what I didn't like about it, as well as the accumulator-centricity. RSL excels in data table display (5/500, not 5000, though that's getting better). TIA lags a little here as well.

>RSLogix is pretty much the
>gold standard for getting right to work. I suppose they'll
>bundle that with crap to program everything I'm unlikely to
>ever see and ruin it too. The current trend for horribly
>bloated do it all packages makes me look forward to
>retirement.

Yeah, the all-in-one thing doesn't appeal to me either. I don't really use Siemens HMI's, and I think they oversell the benefits of the tighter integration. What I like about the current TIA is user-defined types, user defined functions and function blocks, good code protection and copy protection, and that the software seems like a thoroughly engineered professional product. The Click stuff (which I've never actually used for a real project) feels cheesy in comparison.
 
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OK, I got the new Clicks today. There isn't a lot new to report, but that is because it just works. I did have to install a new version of the free software, but I powered one up and plugged it into a switch. Then I went back to my desk and fired up the software. No muss, no fuss, I selected connect to PLC, and Ethernet as the node and there it was. I wrote a small program to send G code out through the RS232 port and downloaded it. No problem. Then I added a few more rungs. No run, stop, run. It just did it. There is a check box so you can uncheck it and do things the old way, but the default was online editing. I have to write the other half that will initiate the transmission via ModbusTCP, but I expect that will work if programming across the network works. There is also an option to use USB which is interesting since the Click doesn't have a USB port. I wonder whether it will or is this just to make it a bit more convenient since the duopoly did in the serial port. I am really pleased, even just the programming over Ethernet is much more convenient.
 
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