Arduino PLC IDE
arduino.cc
arduino.cc
PLCs also replaced a hell of a lot of very unreliable wiring and electromechanical hardware.
But in many cases you have large-ish systems that have various lookup tables in PLC memory, do non-cyclical communication (ie. communicate with something external over some “normal” protocol, not over fieldbus) or even just contain many instances of the same logic (there are PLC families that cannot do indirect accesses to the process image memory, so if you want the PLC to do 12 instances of the same trivial logic, there is no way to do that in a loop and you have to copy-paste that 12 times…). In my opinion for many of these situations just programming the thing in “real” programming language (even while preserving the cyclic process image model) would be very beneficial.
There is a certain amount of pain and inconvenience incurred for a highly deterministic outcome that is otherwise unachievable without very significant expertise.
can you give examples where that is the case? It's hard for me to believe this. The embedded C ecosystem has all the best practices available (software and hardware abstractions, libraries and frameworks, unlimited open source availability, transparent tool chains, testing, build automation, continuous deployment, huge developer pool with shared)
Does PLC match ALL this and even go beyond?
Plus PLC hardware has a level of inbuilt hardware diagnostics that would take months to code and prove from scratch.
ladder logic is painful but works pretty reliably and probably the easiest to learn.
depends on what you want to do and what you're familiar with. in all PLC is a different programming paradigm than you are used to.
the simplest and cheapest way to get into it is probably automation direct stuff or maybe the arduino pro stuff.
TIA portal makes me want to kill myself sometimes, but Siemens AX is now just vscode with extensions!
I assume you don't think 61131-3 ladder/FBD/etc is horrible, only ST? If so, it's just pascal and not C/Algol.
Otherwise seems totally reasonable?
They are similarly priced to the arduino and the hardware interface is several orders of magnitude more robust.
With Ethernet that supports both Modbus TCP and Ethernet/IP, two very standard industrial protocols*: https://www.automationdirect.com/adc/shopping/catalog/progra...
Note: I *HATE* EIP but we're stuck with it in the USA.*
Uh... no.
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.
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...
Standard ones, like distrelec, mouser, TME, etc.
This is not hard
You seem to speaking from the place of someone who actually hasn't done this before.
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.
Let's shove it into octopart: https://octopart.com/search?q=6ED10521CC080BA2¤cy=USD&...
Let's see: distrelec, mouser, tme, etc.
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.
(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 :-)).
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.
If you know what you are doing there are ways to make it easier and cheaper.
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.
And you get fast deterministic control with etherCAT no problem.
Don't sleep on beckhoff
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!".
The weapon of choice of enterprise anything: FUD.
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.
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.
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.
Best of all, no middle men distributors to dick around with. It is so easy to buy their stuff compared to almost all other controls hardware.
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.
No one in their right mind is using this as a product around which to build a machine or a business.
Have 100% used arduino to PoC industrial electronics in a startup setting.
About the only people who seem impossible to get anything reasonably priced from are Allen Bradley, who even have usb->rs485 converters they sell for $1400.
In this case:
1. You can program them in vscode if you want, or using their IDE
2. Their IDE supports git just fine, and that's what i use
3. The languages, like just about all major PLC vendors, are PLCOpen (IEC61131-3) languages. They are well defined.
Vendors differ in what edition of PLCOpen they are up to, similar to how you'd see differences (in the past) in what version of C++ is supported by an IDE/compiler.
Since PLCOpen is not trying to actively add random crap (like C++ is), it's not really a huge treadmill
4. They all have OPC/other standard ways of data access.
It actually scares the shit out of me when I see stuff like this because I know someone naive will use one somewhere completely inappropriate and something bad will happen.
(Ex EE for ref)
Don't do stuff you don't understand. I'm certified in Ex design and Functional Safety and see amateur hour most days.
Like, just put some 220 ohm resistors, PCB spark gaps, and ESD diodes on every pin, and you've covered a lot already.
I'm planning on ordering some PCBs for something similar in a few days, and I'm still confused about why this doesn't exist already.
So many simple cheap things could be done to make Arduino better. Like, connecting individual pins is fun very briefly as a beginner, after that I want nice clean professional r/cableporn.
Give us 3 pin servo plugs or STEMMA connectors for everything.
Put a diode on the USB-C line so I can power it externally without back feeding and breaking the spec.
Maybe figure out your inrush current so I can have some peace of mind that it won't break itself with inductive current spikes.
Maybe stop using crappy blue relays. 99% of DIY projects do not switch 120vac. Why can't we have protected MOSFETs that don't wear out?
Can we quit using a different pinout for ever everything? Just make your module copy something similar. Every little I2C display thingy has a different pinout for no reason, seemingly evenly distributed across all the possible combinations.
Give us a 5v IO pin for addressable LEDs. Why am I still using discreet 5mm LEDs with dead bug soldered on resistors for space-constrained stuff?
Hobby type MCU boards are too deep in the "Hacker" mindset, where the tech is the focus, as opposed to being part of something else.
Adafruit does great stuff, but so many boards are just... Meh.
Anything you build without getting a custom PCB almost always winds up as cable spaghetti even for trivial things, and it doesn't need to be like that.
I hate how many screw terminals appear in the average PLC wiring scheme, but there's really no other way to get things as customizable as the customer wants without servicing a million and a half SKUs. It sucks, but that's the business.
If you make all the IO pins accessible, you'll never protect them all fully or have any room for dedicated special purpose connectors, but if you choose the most common features and only support those you can do a lot.
For the board I'm doing I only have 3x servo plugs or STEMMA connectors, plus an LED strip output, switched 5v output, and Qwiic/Stemma QT plug, plus headers for the most common class D amp and RS485 modules.
That covers about half of all Arduino stuff I've ever done, and leaves a ton of room for onboard features even on a 35x70mm board.
Standard relay is good for 50 million OPs, if you use them within manufacturers ratings.
Just one example, did you know that most relays have a minimum switching current, and if you don't meet it they will fail pretty quickly. I bet you never even considered that.
Unless I know going to want to switch AC or something, or it's a special safety relay.
People who make cheap off the shelf gadgets don't use Omron.
That's actually really interesting to know about the minimum switching current though!
I wonder who's going to be the first to integrate something like VSCode in their dev environment.
The dev tools in the industrial automation industry are so depressing, luckily we have the excellent Ignition (from Inductive Automation) for HMI/SCADA development.
We have actually been getting away from proprietary PLC's just so we can get away from IEC 61131. Its taken a few years but we are about there.
But it's walled behind a license fee. So no ladder for everyone, but rather, ladder for people who are already using ladder and aren't gonna drop their PLCs to adopt Arduino.
Sad.
And further reinforces the "what the hell is Arduino doing" feeling.
My dad had an industrial machine and he coherced the maker to give him the sources and it was done with this versapro thing.
Graphical environment + a gazillion of memory bugs because there were no variables, just memory addresses, and you were supposed to remember how many numbers to skip, depending on the size of the variable.
Over two decades ago I was programming a Foxboro PLC in their SALL language, which was compiled down to C. Variables and control structures! And you could hack the C if you wanted your state transitions to go faster.
In Allen Bradley rslogix it can be entered quickly using the keyboard.
In my opinion the ladder paradigm is poor when dealing with numeric values, and function block better serves the purpose there
Structured Text is superior when it comes to calculations, bit manipulation and code flow (loops, conditionals etc). Sequences diagrams are advantageous for abstracting sequences. Function Block Diagrams are good for connecting abstractions. They all have their place imo, except Instruction List, which I can’t think of having a single advantage.