Decommissioning soon

[Dayvieboy]

Where I'm at now and the stuff we're doing? Well, we can't get a ControlLogix platform to do what we need it to do, let alone a PLC-2, PLC-3, or PLC-5.

90% of our control systems are custom boards designed in house.
So off the shelf PLC limitations are never an issue.

Off the shelf PLC's still have a pretty big place.
They are modular, can be easily rearranged & handle many fairly complex processes.

When you design a custom board it has considerably smaller footprint
but is pricey to modify, add or rearrange I/O.

You have to build & stock them yourself.
You cannot just order a new one from the local supply house.


Another big foothold PLC's have is they can be Safety rated to Sil3 (Cat4) out of the box.

No need to spend many man years to prove that your custom circuit board will safely do what it is supposed to do reliably for it to be signed off.

An EMO (E-Stop) can be sent over Ethernet/IP CIP to multiple PLC's
in both the Fab & Sub-Fab

Safety PLC's are usually requested to be used for most safety related processes in place of custom boards

 

[geniusintraining]

Both my 1968 GTO and 2016 Tesla were made there.

Very nice rides.... I watched the Barrett Jackson 50th over the weekend, they had some GREAT cars

https://www.barrett-jackson.com/Media/Home/Summary/50th-anniversary/

 

[Frost999]

That is pretty cool!!

Possible both frames were drug through the same conveyor
1968 was still a few years before the AB PLC 2 came out in the 80's

Wonder what they had back in 68.
Simple relay logic or some kind or controller?

I replaced a (mechanical) drum sequencer from maybe the 1950s, in 2000, fresh out of school, for a SLC controlled setup.. I had never even heard of one at the time. It managed cars for a tunnel kiln (brick plant), holding area, and dryer.

Over the years they had welded up (built up) the switch cams (bumps) over and over.... ground off and moved some; etc. That's not easy re-programming!

 

[busarider29]

90% of our control systems are custom boards designed in house. So off the shelf PLC limitations are never an issue.

Curious, what specific limitations are you having or have experienced with a PLC for your process?

Off the shelf PLC's still have a pretty big place. They are modular, can be easily rearranged & handle many fairly complex processes.

Yeah, I work in product testing and validation. All the machines we have are for that purpose, and the testing requirements often change, which means that the machine and what it is currently capable of doing often needs to be expanded on. So the flexibility and scalability of the controls platform is an absolute must, while maintaining as small a footprint as possible. I find myself adding various I/O and functionality to these machines all the time.

When you design a custom board it has considerably smaller footprint
but is pricey to modify, add or rearrange I/O.

We design our own control boards too for some applications, where it may be more practical to have a custom board handle the task at hand in lieu of the IPC/PLC. We often then interface the IPC/PLC to the custom control board.

Another big foothold PLC's have is they can be Safety rated to Sil3 (Cat4) out of the box.

Yep. We use TwinSAFE safety in all of our machines. It's all over real-time EtherCAT.

 

[LadderLogic]

That's the technology that put people on the Moon!