What? The IO is digital inputs and outputs, analog inputs and outputs.
Then there’s power distribution and 24v DC device power (or 120v depending on application and often age), relays, contactors, timers, VFDs, etc. This is what the world runs on. Networking cables like that Ethernet are still part of it but a pretty small part. They just get plugged into all the PLC racks and any other device that needs it. Some of what I described can be replaced with automation and code, but only the very old legacy devices a lot of these old plants and mills still have around because they’re still functional…
But then you have many racks that could fail, any one of which taking the system out. So you add redundancies and now you have a small “server room” in each section of the building that needs to be clean enough to inspect devices without getting sut or coal dust on them.
Engineering is about tradeoffs.
Sometimes that means sticking enough RAM in a missile that runes out of fuel first and sometimes you run a lot of cables, but make up for it in reliability and easier maintenance.
Yeah, exactly. You definitely save some copper by running ethernet to remote racks but by raw wire count it’s not reduced much. There’s a LOT of modern plants (power and manufacturing plants) that have way more wiring than this in a photo
Who would win? An over-stuffed cable tray, or 4 twisty bois?
What? The IO is digital inputs and outputs, analog inputs and outputs.
Then there’s power distribution and 24v DC device power (or 120v depending on application and often age), relays, contactors, timers, VFDs, etc. This is what the world runs on. Networking cables like that Ethernet are still part of it but a pretty small part. They just get plugged into all the PLC racks and any other device that needs it. Some of what I described can be replaced with automation and code, but only the very old legacy devices a lot of these old plants and mills still have around because they’re still functional…
This is the only comment which mentions PLCs, and wired PLCs are what industries used for decades.
My point (if you can call it that) is that you can have remote racks and cut the total footage of wire by 75%
But then you have many racks that could fail, any one of which taking the system out. So you add redundancies and now you have a small “server room” in each section of the building that needs to be clean enough to inspect devices without getting sut or coal dust on them.
Engineering is about tradeoffs.
Sometimes that means sticking enough RAM in a missile that runes out of fuel first and sometimes you run a lot of cables, but make up for it in reliability and easier maintenance.
Yeah, exactly. You definitely save some copper by running ethernet to remote racks but by raw wire count it’s not reduced much. There’s a LOT of modern plants (power and manufacturing plants) that have way more wiring than this in a photo
I mean nowadays yes but the pic has some old relays in it, I’m fairly sure the DCS/PLC is not ethernet if there even is one