Like a lot of Arduino products, it must be targeted at people who don't know any better and whose sole exposure to electrical engineering or systems engineering is what they see in make videos. Automation direct PLCs are cheaper than whatever they're hawking here and almost certainly way more robust (having used a few, they were surprisingly good). Anyone who is using PLCs in a remotely serious industrial fashion is almost certainly going to keep buying Rockwell or Siemens anyways.
> Like a lot of Arduino products, it must be targeted at people who don't know any better and whose sole exposure to electrical engineering or systems engineering is what they see in make videos.
Industrial automation is exactly this. If you look up the history of the PLC, Dick Morley, founder of Modicon, specifically designed it to hide the computer part. The reasons were twofold: partly for marketing as in ye olde days computers were big, expensive and required costly engineers, and to enable plant electricians and other maintenance personnel the ability to program them using ladder schematics which is why we have ladder logic. So from the beginning the PLC has been targeted at non-technical personnel.
> Automation direct PLCs are cheaper than whatever they're hawking here and almost certainly way more robust (having used a few, they were surprisingly good).
Indeed, though I only like the Click. I have two Clicks at home and used them at work for all sorts of little projects. I haven't bothered with their Productivity line as I dont think it's a very forward thinking platform as its stuck in the 90's with parallel busses on backplanes with proprietary expansion (literally a clone of their Koyo DL series). Then there is their legacy Direct Logic series from Koyo which is solid as hell but long in the tooth. Now they are selling LS Electric which makes me feel they are all over the place PLC wise.
For bigger automation projects I use Beckhoff gear which is very modular and their EtherCAT protocol is very well designed and thought out - deterministic structs over Ethernet. My only gripe is the big shitty Visual studio shell IDE that tends to fall over but every automation vendor has big shitty IDE's. Thankfully they have a FreeBSD runtime alternative to Windows Embedded for the controller side. I can write real-time PLC programs in C/C++ and whatever on the Windows/BSD side. Or stick with IEC 61131-3 languages.
> Anyone who is using PLCs in a remotely serious industrial fashion is almost certainly going to keep buying Rockwell or Siemens anyways.
That is more of an industry trope: "no one ever got fired for buying IBM" but replace IBM with AB for the USA or Siemens in Europe. Basically, Enterprise grade automation with all the associated enterprise goodness: high cost, licensing, price gouging legacy support, and poor technical decisions. I stay away from it.
Seconding Beckhoff. EtherCAT is a fantastic protocol, TwinCAT/BSD works great, reliability is excellent. It's super nice to run realtime PLC code on specific processor cores with µs of jitter while other cores run a normal OS with normal applications (e.g. VictoriaMetrics) on the controller itself.
I have a construction project involving several buildings with overlapping infrastructure. Everything gets connected to EtherCAT as quickly as possible. Electric generation: solar panels, batteries, inverters. Energy management: branch circuit monitoring, weather forecasts, solar forecasts, load control for things like EV charging and water heating. HVAC: heat pumps, buffer tanks, circulation pumps, valves. Building automation: lighting, access control. I just add I/O wherever, connect over Ethernet, and glue all the signals together in software.
I wouldn't dare approach a project like this with Arduino.
It's… fine? Unlike certain other brands, I've encountered no network of frothing, territorial, gatekeeping dealers with Beckhoff. For my project, I reached out to sales.usa@beckhoff.com, got a rep, asked for a quote, and went from there.
Secondhand can be viable too. Some of my "jellybean" EtherCAT terminals came from eBay. I won't get help from Beckhoff if they break, but given that I already have replacements on hand, I'm really not worried about it.
Beckhoff also lets you download almost all the development tools, runtimes, and PLC libraries without paying. In their words:
> Trial licenses can be generated in the TwinCAT 3 development environment (XAE) for many TwinCAT 3 functions for a validity period of 7 days. This can be repeated any number of times. An internet connection is not required for this. In this way, these TwinCAT functions can be used simply and cost-effectively in laboratory operations, e.g. in the education sector.
This is obviously useful for development and experimentation. It can also be an escape hatch in production if you need to substitute controllers. Beckhoff wants you to pay for what you use, sure, but their licensing scheme goes out of its way to avoid kicking you when you're down.
> Unlike certain other brands, I've encountered no network of frothing, territorial, gatekeeping dealers with Beckhoff.
This. They sell you gear then leave you alone. If you need help you call or email. Done. If the vendor demands you create an account to access simple datasheets - run like hell. Once they see you even glancing at a product they activate a frothing at the mouth sales rep who will launch a harassment campaign where they email and call multiple times a week seemingly forever or until you are EXTERMELY rude to them.
There's also this really weird fear in that industry of open-source anything.
A while back, I was investigating security options for PLCs (in the light of e.g. stuxnet), and while Siemens and Rockwell do ultimately feature such things, there was always a lot of "you can trust our security schema, but you can't trust that open-source stuff, anybody could put anything in there".
There are very good reasons to use PLCs, that the Arduino PLCs completely fail to address. But I'll bet that a lot of criticism within the industry will come down to "its open source, so you can't trust them!".
Beckhoff is so awesome. I bought at least 100 of their EP series modules, which are IP65 and can be mounted anywhere and use M12 and M8 connectors, so with the right sensors you can just connect with an off the shelf cable, no wiring connectors. No running endless sensor and actuator cables back to a central cabinet.
And you get fast deterministic control with etherCAT no problem.
There may be competing products, but you can't go to a screwdriver shop today and buy quantity=1 to learn from, which vendors should have accommodated even at some substantial margin.
Any large supplier will hapilly sell you one PLC of any type (there are also quite a lot projects needing just one piece of specific PLU), the tools might kill your budget though. And there are special beginner/low scale series like Siemens LOGO with simplified configuration and cheaper simpler tooling.
Call your closest electrical supply and get the price. Plant maintenance technicians are comparatively old-timey, so ask yourself how you would do it in 1990 and try that.
And for the record, brand new Logos are like $100-$200 on the low end and you probably shouldn't use them. The low end of S7-1200 will come in between $500-$1000 and is much more likely to fulfill your needs.
Sure, call. Do a back and forth with calls and emails for two days with their sales guy to make sure they got it right. Spending five to six figures. 5-15% of order shows up incorrect.
When you go to try another distributor: No, you're in crappy vendor's territory. So, sorry!
Waiting for that invisible hand of the free market to step in...
As i just posted, in this case, all you have to do is paste the part numbe rinto octopart and you would discover there are 5 no-questions-asked distributors that will sell you it without any issue.
I guess I'm fortunate enough to have never had any issues with the local yokels and haven't run into anybody with any distributor horror stories. Save Keyence, of course, but at least their salespeople are so desperate for sales that the salesman you have at any given time will usually let you walk all over them. AB's licensing entitlement processes have always given me more grief than distributors. If it's any slight consolation, there are at least a few places in the world that don't have too bad.
This is the distributor website
Which they publish the entire catalog for (unlike some others). If you are a distributor, there actually is a buy button on the same page.
You can get them at mouser, digikey, and a million other places.
Seriously, this is not hard.
Let's take the first thing on the page. Part number 6ED10521CC080BA2.
You really seem to be making this out to be hard and it's super easy.
Siemens PLC stuff is really really easy to get.
I can't name a single PLC thing i could not get shipped to me overnight, from RS or mouser, without talking to anyone.
The only thing that requires actually talking to siemens is some of the CNC stuff, and there, it took me 1 day to set up an account and i just email them PO's, they auto-send me ship dates within an hour, and they invoice me later.
So even that is not like "this person tries to hard sell you on stuff". Heck, I sent them a PO today for 90 laser-inscribable keycaps for a machine control panel, not exactly a high value item. They are happy to do it.
Now, i happen to live near automationdirect, and their stuff is quite nice for simple things, but if you are integrating into the siemens ecosystem, it's just not that tricky to get stuff.
Or you can register as a customer if you work for a company that is deemed "worthy". I have full access to their prices and I can buy stuff directly from Siemens.
(Well, except for motor controllers that operate at higher frequencies. For that I need the approval of various government bodies as well as international organizations tasked with ensuring non-proliferation :-)).
Thanks, I hadn't seen any of those names before today, not being an experienced embedded builder. I used to browse Radio Shack, Fry's, and Micro Center for breadboards and stuff, but they all shut down over time, as did Halted Specialties (before I heard about them).
I've spent some time (not a lot) working with Siemens PLCs and RTUs. Their target customer typically has an account manager who will help them choose the right devices, the right modules and the software that you need. Their typical customer also has a significant budget for automation systems and they usually build systems that are mission critical. Like a production line.
Getting an account at Siemens requires a bit of work. They want to know who they are dealing with because a lot of their hardware is export restricted. Some of their hardware they can't even sell you without explicit government licenses. (For instance, motor controllers are tightly regulated when you get to the high RPM stuff since that can be used in gas centrifuges - ie to enrich uranium).
If you have an account with Siemens you can get prices. Also, it isn't exactly your run of the mill shopping experience. I may misremember some things since it is a couple of years since the last time I bought something from Siemens, but you typically create a "project" and then add components to it. It will then validate the stuff you have picked and point out what additional modules you need, what software you need, if this doesn't work with that etc.
You can kind if imagine a PC shopping experience where you buy parts to build a PC and it will automatically ensure that all the components will work together and help you figure out what choices you can make.
Once you think you have pieced together what you want, you typically talk to a solution engineer at Siemens and you go over it together. I bought various components for a small system, and still, I got excellent service. You get to talk to a person who can look over your order and make recommendations within a day or two. I was really impressed.
If you spend millions on automation gear (which one of my consulting customers do) this is the kind of relationship you want with a vendor. You want both the help from the website itself and a solution engineer who can help you make the right choices. And you want it in a timely manner.
Also note that I'm essentially an amateur in industrial automation. People who do this for a living often have many years of experience with this equipment. If, like me, you come from the outside, the website is rather daunting. Just picking the right PLC is going to take a couple of weeks of learning about them before you know what you are looking for. Then you need to figure out what software tools you will be needing to program, operate and maintain your installation.
That being said, their website could do with a makeover. It is unnecessarily hard to find things, the design and use of tiny fonts is ugly and annoying and it is slower than it needs to be. The software is also a bit clunky to use. But it helps understanding what audience it is aimed at. If you are trying to automate your hobbyist beer brewing setup, this isn't for you unless you are prepared to spend a pretty penny and invest time in learning how to program these things. It isn't that hard (it took me a couple of days to cobble together a PLC, a HMI a (third party) motor controller and make 40kg industrial motor do what I wanted), but it is completely overkill for a hobby project.
Yes, there is the LOGO line, but after playing with it a bit, I don't actually understand the point of it. It is too separate from their Simatic S7 line to work as a useful learning tool if you want to ease into the professional stuff, it is too limited to be much fun and it is too expensive. Of course, if you are controlling high power systems you do want equipment that is built to high quality standards.
Yes, the Arduino world has nothing in common with industrial automation hardware. For one, the amount of effort that has gone into delivering guarantees and meet certification criteria in automation hardware is miles beyond what you'll find in hobbyist MCU systems. (A good way to understand this is actually to look at the writeups of the Stuxnet attack. This gives you a good background in how Siemens industrial systems are engineered and what it takes to break them).
But I wouldn't shit on Arduino for doing this. Think of it as a somewhat cheaper entry level into teaching industrial automation and help people use it in hobbyist projects, prototyping on tight budgets or even doing small hobbyist setups. The professional stuff exists. There are lots of vendors. But it requires a lot of training and it costs a lot of money. There is a legitimate place for lower spec systems.
It can also play an important role in helping the industrial automation giants improve their products. It can, and will, generate ideas that, if the giants are smart, they can learn from. As in most of these professional/amateur interfaces between people, the professionals will scoff at this. But that doesn't matter. They're likely myopic and wrong.
I can remember back when Oracle wasn't ported to Linux and the database professionals scoffed at the idea of Oracle offering their database for Linux. (Yes, there was a time when that was the case). They were wrong. Not because they knew what they were talking about, but because they were snobs. And as it later turned out (after I spent a few years designing database schemas and optimizing databases) most of them weren't even particularly good at their jobs.
I think the same thing is going on here. Seasoned professionals with perhaps decades of experience with industrial automation, tend to not have the necessary perspective, which can lead to stagnation. I see this in, for instance, integration beyond traditional SCADA systems. Providers like Siemens have to adapt to new requirements of faster, cheaper, more open, more accessible integrations and a lot of the "old guard" simply have no frame of reference for understanding these things. For instance they have no idea how software engineers work, how fast processes need to be, and how much "self service" is expected. This is frightening and confusing and thus, from where we stand, it looks like silly snobbery.
I hope that my observations as an outsider getting tangled up in industrial automation and dipping my toe into that world might help people make sense of things.
Sure, the Arduino stuff is amateur hour, but it is still immensely valuable because it provides opportunities to advance the industrial automation, MCU and software worlds by exposing people to ideas, problems and solutions from outside their own bubble.
When I've bought Siemens gear in recent years the panel builder buys it for me, at prices I could never get, and deals with all the returns, late deliveries etc etc, they hold the Siemens account.
If you know what you are doing there are ways to make it easier and cheaper.
I second your opinion on Automation Direct PLC. I use a few of them in an installation for a museum 15 years ago and they had a surprisingly good reliability/feature/price ratio.
Maybe, Beckhoff are cheap, got a good programming environment and programming software is free, plus their simulator is so good you don't need hardware until commissioning. In Australia you can buy them at Blackwoods (Plumbing and general supplies with over 60 stores) who hold good stocking levels.
And there are others, Omron, Mitsubishi, Wago etc.
Allen Bradley is unreasonably expensive below a certain scale that isn't small and Siemens is not much better - you can easily blow 20k on just a single CPU module, and TIA Portal on a preconfigured laptop is 20k.
Rockwell (for AB programming) has changed to subscription model, but last time I had to buy Studio 5000 is was 10k for ladder and another 10k for the other languages.
Plus a PLC won't run of a battery for a month, or a year, but a microprocessor will, it is all about your use case.
