L
Leonard Misner
"PC with a simple robust OS" is an oxymoron.
there is no blue screen of death on a PLC.
You can talk about how fast your PC is and how it runs circles around that x86 PLC...until you have your PC running soft PLC, driving animated graphics, handling a hundred analog process devices, calculating statistics and creating paretos and productions reports...and when you can't even get 4 temperature samples while attempting to monitor a single analog device at a tenth-of-a-second sample rate, then tell me how a pc is any comparison at all to a plc. Consider: Why does a PLC exist at all? Why was it created? If a PC architecture is EVER the optimal option, how does 'plc' ever exist and continue to exist? Do you have some magic PC that doesn't slow down whenever you open more and more applications?
A pc is a single tasking slow stupid device which is incapable of having a few hundred process applications running simultaneously while still processing the entire program, scanning all I/O and updating the image table repeatedly and absolutely reliably at a rate of a few milliseconds even with the plc sitting alone in an oil saturated box for decades at a time.
Yes...there are industrial pc's...but they're still limited by their architecture. I'm speaking from 10 years experience leading multimillion dollar plc based automated assembly and test systems internationally from concept through 6-sigma runoff...add another 25 years of working with automated systems in automotive, pharm and food manufacturing facilities - both plc and pc based systems. Test engineers cry whenever I point out that even their test stands (typically pc based controls) can be done easier and more reliably with a plc. One of the biggest reasons the United States has had so many manufacturing plants closed down is because we simply have lost the ability to being competitive in the world market. You have to get the best quality product out the door at the lowest cost. that's a pretty simple concept, but it seems so many engineers believe the company they are working for is there to facilitate their own personal technical experimentation and entertainment. Not nearly the challenge of a PLC application then to do all that forced integration and special configurations and code of most pc systems. You have mentioned how a PLC is more readily supported, more easily programmed by more people who have that knowledge, ethernet integration is simply a module and copying some config junk from a manual as you suggested. So why would intentionally compromise the future of the company you're working with by forceably integrating a pc with various uniquely concepted techy toys that were NOT DESIGNED SPECIFICALLY TO the task of reliable machine control. If you (or the support team left in your dust) can access your controls, understand the process as programmed and have an ability to improve analog monitoring and controls...then you can improve product quality and production efficiency. The market wants to buy less expensive golden nuggets...not some terd product that was produced by a "black box" that nobody can work with to make that terd product any better than the terd product that it is. If your stuff can't compete in the market, your company shuts down...welcome to America. Engineers are supposed to be a pretty sharp group...why haven't they figured THAT out?
Anybody ever hear of Dr. Deming? ...don't get me started. lol.
there is no blue screen of death on a PLC.
You can talk about how fast your PC is and how it runs circles around that x86 PLC...until you have your PC running soft PLC, driving animated graphics, handling a hundred analog process devices, calculating statistics and creating paretos and productions reports...and when you can't even get 4 temperature samples while attempting to monitor a single analog device at a tenth-of-a-second sample rate, then tell me how a pc is any comparison at all to a plc. Consider: Why does a PLC exist at all? Why was it created? If a PC architecture is EVER the optimal option, how does 'plc' ever exist and continue to exist? Do you have some magic PC that doesn't slow down whenever you open more and more applications?
A pc is a single tasking slow stupid device which is incapable of having a few hundred process applications running simultaneously while still processing the entire program, scanning all I/O and updating the image table repeatedly and absolutely reliably at a rate of a few milliseconds even with the plc sitting alone in an oil saturated box for decades at a time.
Yes...there are industrial pc's...but they're still limited by their architecture. I'm speaking from 10 years experience leading multimillion dollar plc based automated assembly and test systems internationally from concept through 6-sigma runoff...add another 25 years of working with automated systems in automotive, pharm and food manufacturing facilities - both plc and pc based systems. Test engineers cry whenever I point out that even their test stands (typically pc based controls) can be done easier and more reliably with a plc. One of the biggest reasons the United States has had so many manufacturing plants closed down is because we simply have lost the ability to being competitive in the world market. You have to get the best quality product out the door at the lowest cost. that's a pretty simple concept, but it seems so many engineers believe the company they are working for is there to facilitate their own personal technical experimentation and entertainment. Not nearly the challenge of a PLC application then to do all that forced integration and special configurations and code of most pc systems. You have mentioned how a PLC is more readily supported, more easily programmed by more people who have that knowledge, ethernet integration is simply a module and copying some config junk from a manual as you suggested. So why would intentionally compromise the future of the company you're working with by forceably integrating a pc with various uniquely concepted techy toys that were NOT DESIGNED SPECIFICALLY TO the task of reliable machine control. If you (or the support team left in your dust) can access your controls, understand the process as programmed and have an ability to improve analog monitoring and controls...then you can improve product quality and production efficiency. The market wants to buy less expensive golden nuggets...not some terd product that was produced by a "black box" that nobody can work with to make that terd product any better than the terd product that it is. If your stuff can't compete in the market, your company shuts down...welcome to America. Engineers are supposed to be a pretty sharp group...why haven't they figured THAT out?
Anybody ever hear of Dr. Deming? ...don't get me started. lol.