Soft PLC's taking over?

[jraef]

Soft PLC + BSOD= total disaster...

 

[busarider29]

Soft PLC + BSOD= total disaster...

Who's getting BSOD??? I mean, I get one occasionally on my laptop, but have yet to get a single BSOD on any of our Beckhoff machines, of which have been running 24/7 since 2014. Furthermore, we have machines built by MTS that use their proprietary hardware and software and are all PC based. Never a single BSOD on any of those and they are standard desktop PC's, not industrial IPC's.

Nothing is perfect and neither are soft PLC's. You can cherry pick something wrong with anything. But the BSOD argument is a thing of the past, like late 1990's past, and doesn't hold much water anymore. Pretty much a moot argument now. What else you got?

 

[daba]

So, define a "soft" PLC ....

Does that mean it runs under Windows, Linux, MAC OS, or any other platform you care to mention ?

Does "soft" mean it has to load from disk, HDD or SSD ?

Does it mean that the OS is "generic" and not tailored to the task the CPU performs ?

I don't believe this is a way forward. PLCs are specialised and dedicated to one task. They must survive power outages, they must survive being underwater (yes, it has happened to me), they only have one job to do, so why complicate it by making it "soft" ?

 

[lfe]

A hybrid alternative:
Mitsubishi years ago sold a PCI card that was a PLC by itself, running independent of the PC CPU, inputs and outputs could be added via an extension cable

https://www.amazon.com/A80BDE-A2USH-S1-MITSUBISHI-A80BD-A2USH-S1-CARD-A2USH-S1/dp/B01D1FJ7PO

 

[Steve Bailey]

I was working in the automation field during the time when PLCs were taking over from relay controls. I don't recall the transition from relays to PLCs taking as long as transition from hard PLCs to soft PLCs has taken. I also don't remember articles in the trade magazines telling us why relay control was never going to go away.
Hard PLCs will go away when something better comes along to supplant them.

 

[mk42]

Soft PLC + BSOD= total disaster...

I haven't seen any soft PLCs in a a decade that would be troubled by a BSOD.


Most that I've seen have a divided kernel or a full hypervisor type setup, if they include Windows. If they don't include Windows, I feel like those sorts of problems are less likely anyway...

 

[Rob...]

We've been using Siemens microbox and nanoboxs successfully for years now.

Never had any issues.

 

[daba]

Hard PLCs will go away when something better comes along to supplant them.

"Something better" - I don't know how you can achieve "better" than a dedicated microprocessor-based product that performs exceptionally well, does its job admirably, in most cases can be field flashed to a later revision, doesn't need HDD or SSD storage, is generally invulnerable to hacker attack ....

I suppose it depends on the vague definitions of a "soft" PLC. We all know they run "soft"ware, mostly from Flash Ram.

If you put a soft PLC into a system, the night-shift operators will find a way to run Tetris or Soldier of Fortune on it. (That was a tongue-in-cheek joke by the way).

Mitsubishi years ago sold a PCI card that was a PLC by itself, running independent of the PC CPU

I wouldn't call that a "soft PLC", that just a hard PLC drawing power from the PC, and we all know how often PC power supplies leave the room ....

Furthermore, we have machines built by MTS that use their proprietary hardware and software and are all PC based. Never a single BSOD on any of those and they are standard desktop PC's, not industrial PC's

A "standard" desktop PC's power supply is built to as low a cost as possible. List price of a ControlLogix PA75 power supply in the UK is £759.00 (over $1000) .... I rest my case ...