Distributed I/O: Automation Tech Talk for August 27, 2025

Shawn discusses generations of Rockwell IP20 distributed / remote I/O in today’s Automation Tech Talk, Lunchtime Edition:

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Shawn Tierney (Host): Hey, everybody. Welcome to Automation Tech Talk. I’m Shawn Tierney from Insights, and I’m about seven minutes late today. I just got off a, really excellent call with a major automation supplier, actually, automation manufacturer, who, was introducing me to his next generation IO. And, so I didn’t have a lot of time to prep, and I’m like, what am I gonna cover today?

And I’m like, let’s talk about distributed IO. So that’s what we’re gonna talk about. I love to hear in the chat where you what you guys are using for distributed IO if you’re using distributed IO. Now OEMs typically don’t need distributed IO. I mean, don’t get me wrong.

They will, oh, and I should also say if you guys can’t hear me or you can’t see me or something’s wrong, let me know. But in any case, typically, an OEM with a small machine, they don’t need the distributed IO. Now they will run a lot of times Ethernet through their different devices like VFDs and HMIs, but, they don’t need distributed IO. However, a facility with a large machine or a large system, it makes no sense to run all the wires back from all the sensors and switches and buttons all the way back to the main panel, and that’s where distributed IO really does extremely well. And, you know, PLCs and PACs more and more can handle even more and more higher quantities of distributed IO.

But before we get into that, I thought we would talk a little bit about the history of distributed IO or remote IO as Rockwell coined the phrase or patented the phrase back in the day, back in the late seventies. In any case, in the first distributor IO I saw out there, saw a lot of it out there, was seventeen seventy one. And seventeen seventy one IO was, big and bulky. This is an eight point module. I just grabbed what I had available, you know you know, with two minutes to go before the show started.

Let’s see if I set up the overhead cam correctly. So I do not have the terminal block on here, but this is an 8.1771, IO module that was donated to, somebody who then donated it to me. And, thank you to both of companies for the donation. And I have a ton of this stuff, and, it’s really super inexpensive online. But the, you know, the problem is the programming software is so expensive.

So, you know, a lot of people could use this, reuse this stuff for hobbies or whatnot. But, in any case, this would fit in a big, jack. You guys have seen the racks here before, the big seventy seventy one chassis, and we don’t call them racks. We call them chassis. And, you know, it worked.

Remote IO definitely worked. The the digital was so easy to set up. The analog, a lot of people had a hard time getting their mind around block transfers. I always felt that I could explain it to people easily, and that’s why I’m doing a PLC five course with seventeen seventy one IO. I don’t have that on here on the stage because it’s just so big.

I actually have it over there on the floor. But in any case, you know, of this you see this a lot. I remember going to one power plant and walking through and and, because they wanted to migrate all this seventeen seventy one IO and just taking pictures and pictures and pictures of MCC is full of distributed IO racks with remote IO and seventeen seventy one IO. And as I was going through there in the seventy eighth rack of IO, I’m like, this is not affordable. This stuff, first of all, it’s bulletproof.

Why replace it? Second of all, I mean, I don’t want my electric bill going up just so they could say, we have new stuff in the enclosure. So in any case, a lot of times no. I don’t know. I will I won’t go I’m not gonna go down that that route.

But in any case, so 1771 was the first distributed IO I ever I ever, came across. And then, of course, there’s there’s all the stuff, and I’m just covering Rockwell today. This vendor who I met with who has next purely I mean, really, next generation, distributor IO, I’ll be doing a video on. I have a box of this brand new stuff they sent me. They sponsored some coverage on it so I can make the video and keep the lights on at the same time, so I’m excited about that.

But in any case, the next one I ran into was block IO. So this is some of the original block IO, remote IO. Again, a lot of times these IOs were available on multiple different networks, like device that control net, remote IO. But in any case, let me see if I can go back, over to the overhead cam and maybe even zoom in a little bit here. Again, I’m doing this all ad hoc.

Here’s some original block IO. Check a look at that. And, man, this brings back memories, but these are actually fairly easy to use. And, you know, being all in just one little package, you know, pretty awesome. Pretty pretty awesome, distributed IO.

And so that was block IO. So now we move forward. We really had, something called flex IO. Now all my flex IO I’m using this as a stand in. This is really just a, a, drone that adapter for the flex IO.

But, in any case, this would be the control that had all my Flex IO, my Ethernet Flex IO, it’s all at home. I’m building up new demo boards for the automation school. But in any case, Flex IO was very popular because it was, of course, modular unlike the, block IO and not and small unlike the seventeen seventy one IO. And you could do up to eight of IO modules on a single, adapter or network head, network, interface module. And, yeah, pretty cool.

The modules, again, I have it all at home. So but the modules are separate from the terminal blocks, so the module would come off. The terminal block would stay. A lot of people like that. And, very, very popular.

You could also one of the one of the few things of Rockwells that you could mount, vertically as well as horizontally. I see a lot of people mounting, new stuff vertically, like, CompactLogic stuff for you can’t do that. So you gotta check the book out. You don’t wanna get, in trouble with your customer. Now FlexiO, it had some issues definitely on, device stat.

Okay? There were some things where it kinda did a boot up the first time and read in the modules, and if you don’t have them all plugged in, you had to reset it and went through that whole thing in the nineties. But, in any case, very reliable. I like it on all platforms. And, the only one thing it had that was really, like, the, when it first came out.

Right? So, like, when it first came out, everybody was bending these little pins. Let’s see if we can do the overhead camera again. I don’t know if I can get them that close. These little pins that connect the, the units together, everybody would bend them when they try to put the units together.

And you may say, Shawn, how would they do that? Well, if your DIN rail wasn’t perfectly flat, right, was twisted a little bit, then your modules weren’t lined up perfectly, and the pins would get bent. Now you can unbend them if you’re careful. If you break them, throw it away. You know, you got, I don’t know, $500, a thousand bucks worth of junk.

But in any case, that was one of the things that, I didn’t like about this platform. You just gotta be very careful assembling them. Make sure they’re all very flat and lined up before you slide the slider over. Really, that was the only thing I really didn’t like about them. But, again, in the chat, please, please put your and I got a comment in here from Emmanuel.

Hey, Emmanuel. Good to see you again. It wasn’t inexpensive when it was yeah. True true that. True that.

So that is a flexile. And and something that came out that really, and I’m not covering the on machine aisle. Again, all my on machine is at home. I I do have one PC out, but it looks like, not worth showing. So, that would be the machine mount IO that’s like IP 67 or IP 69.

Another unit that came out was Point IO. Point IO is extremely popular, and let’s see if we can zoom in on this guy. And I really like this now. There are some caveats with this too. Don’t don’t try to flash your, module’s firmware.

Not that anybody does that. Right? Most people would never flash their modules firmware unless you found that the chain the, whole blast state isn’t working, and then you’re panicking because your exhaust vents aren’t exhausting poisonous gas. You’re like, I need a last state to work. And then you go to, blast of firmware.

I think they actually don’t let you do it anymore because you could brick it if you are browsing the backplane that this sits on with IrisLinks. The flash would actually break the unit. And so, I know I can’t stand in the middle here. I keep going back and forth, but in any case, you guys don’t need to see me. Right?

Yeah. That’s better. So in any case, very popular platform, never flash the firmware on the IO module so you could break it if you’re browsing the same rack with RS links, but I don’t have the terminal block on here. The other thing that, with point I o that was kind of a bummer, you can se