PC plc´s

Hi all

My company is thinking to change from old style PLc´s to a PC PLC´s

Now mitsubish Q02 and ABB PM571

To Beckhoff CX1030

That are you opinions?

• Do Pc "work" 24/7/365
• Programing style are there big changes (scantimes)
• Other things to be aware of

Are we making a mistake ?

lbg_dk said:

Hi all

My company is thinking to change from old style PLc´s to a PC PLC´s

Now mitsubish Q02 and ABB PM571

To Beckhoff CX1030

That are you opinions?

• Do Pc "work" 24/7/365
• Programing style are there big changes (scantimes)
• Other things to be aware of

Are we making a mistake ?

Click to expand...

I dont know the Beckhoff system but used the Mitsubishi one a few years back, my responses would be:

Do Pc "work" 24/7/365

I think you probably already know the answer to this one !!

Programing style are there big changes (scantimes)

Programs the same as the PLC but runs on a PC, see above

Other things to be aware of

See above

Are we making a mistake ? I would say yes but you know your process better than anybody, its a big decision for sure.

Good luck

lbg_dk said:

My company is thinking to change from old style PLc´s to a PC PLC´s

Now mitsubish Q02 and ABB PM571

To Beckhoff CX1030

That are you opinions?

• Do Pc "work" 24/7/365
• Programing style are there big changes (scantimes)

Click to expand...

Unless you truly need the speed, I would use a CX1020 because it does not have a cooling fan therefore no mechanical parts. I have used the CX line for years in many applications that run 24/7/365 and they are just as reliable as any PLC. I would recommend Windows CE, because it curbs the urge to load unnecessary software and not prone to common PC viruses.


You may find the programming harder to get used to simply because the more capabilities and functions something has the more complex it generally gets. This will give you a quick ten minute look at the software:

http://www.youtube.com/watch?v=l_nFE9wx8OM

In my opinion, no mistake if you are open to learning a new platform. If you get in depth with the software, you will find some nice advanced features that were not possible or very difficult with conventional PLCs.

Archie said:

Unless you truly need the speed, I would use a CX1020 because it does not have a cooling fan therefore no mechanical parts.

Click to expand...

We have a meeting with a sales person in about 14 days. By then I know something more which model I need. But I hope that the model we need will be without fans.

I have used the CX line for years in many applications that run 24/7/365 and they are just as reliable as any PLC. I would recommend Windows CE, because it curbs the urge to load unnecessary software and not prone to common PC viruses.

Click to expand...

It sounds good that you have a good experience with uptime. We are accustomed to the PLC can run at least 5 to 10 years without the need to reboot.

This will give you a quick ten minute look at the software:

http://www.youtube.com/watch?v=l_nFE9wx8OM

Click to expand...

I have already looked at your videos. It's great that some will show their knowledge. So thanks for the videos.

tragically1969 said:

Do Pc "work" 24/7/365

Click to expand...

I think you probably already know the answer to this one !!

Click to expand...

If it was windows 95 will the answer be NO.

But is the Windows CE not a MUCH better product? .

Are we making a mistake ? I would say yes but you know your process better than anybody, its a big decision for sure.

Good luck

Click to expand...

Thank you. I am grateful for all the input I can get.

Personally i wouldnt rely on a Windows operating system of any sort to operate process critical applications, fine for monitoring via SCADA etc. but if you truly NEED 24/7/365 uptime then surely it has to be a PLC ?

What is the application that is being controlled ?

It would be inteeresting to see a few more replies on the subject as i am sure other people have had to make this decision in the past too.

tragically1969 said:

Personally i wouldnt rely on a Windows operating system of any sort to operate process critical applications, fine for monitoring via SCADA etc. but if you truly NEED 24/7/365 uptime then surely it has to be a PLC ?

Click to expand...

In all fairness, it is important to realize that a system like Beckhoff TwinCAT does not run "on Windows" - it runs under its own real-time OS which, when it can, yields to Windows. So it is not "TwinCAT running on Windows" but rather "Windows running on TwinCAT". Or something like that

I think any plan for a radical change of the systems has to start slowly, step-by-step, with caution. Try to convert one of the units, see what it takes, watch how it works for a while. Then you would be in a better position to advise your bosses on which way to go in the future.

LadderLogic said:

In all fairness, it is important to realize that a system like Beckhoff TwinCAT does not run "on Windows" - it runs under its own real-time OS which, when it can, yields to Windows. So it is not "TwinCAT running on Windows" but rather "Windows running on TwinCAT". Or something like that

I think any plan for a radical change of the systems has to start slowly, step-by-step, with caution. Try to convert one of the units, see what it takes, watch how it works for a while. Then you would be in a better position to advise your bosses on which way to go in the future.

Click to expand...

Yeah thought it would be something like that, the Mitsubishi one we used ran on its own kernel, thats fine until the windows kenel falls over and you have lost your GUI !!

Originally posted by tragically1969:

Yeah thought it would be something like that, the Mitsubishi one we used ran on its own kernel, thats fine until the windows kenel falls over and you have lost your GUI !!

Click to expand...

So what you're really saying is that you don't want your HMI on a Windows platform. It sounds like the RTOS kept going just fine.

I had the same type of experience with VLC from Steeplechase. The RTOS was about bulletproof. But Windows really doesn't like to have control taken away from it. What this infers is you may not want your HMI on the same processor as your control.

I view the Beckhoff CX1000 line more like a plc than a PC. While I'm sure you can load all sorts of garbage on it the device doesn't lead you to do that like a desktop PC would.

I think the device and the RTOS are not the issue. Getting used to TwinCat will be the biggest challenge.

Keith

kamenges said:

I view the Beckhoff CX1000 line more like a plc than a PC.

Click to expand...

I completely agree and especially the Win CE based models. What most don't know is that although Windows CE carries the "Microsoft Windows" name, it is not based on the desktop software. Windows CE is it own operating system and IS a real time OS, so it doesn't need a modified kernel to run TwinCAT in real time.

Ah, Windows CE, didn't I read somewhere that CE stands for "Cr@p Edition" !

Quite frankly I would run away from the proposed solution at a million miles an hour if machinery or critical applications are involved.. PLCs are industrially hardened devices and very reliable.
There are industrially hardened computers around as well but when you see some of the complete messes made by PC component suppliers you wonder what you have under the bonnet.
Take for example the recent problems Dell and HP have had with 'dud' nVidia chips that were frying motherboards (I had one).
The issues in the past when Intel chips did not calculate properly.
There are many others.
Then if Windows stuffs up again and you have to turn the computer off with the big red button or the reset button, it does not matter that the PLC system has it's own OS, it will turn off and re-start as well.
The only thing I would consider for any critical application in a PC would be a PLC on a card that plucs into a computer slot with a separate 24VDC power supply to the card. Run remote I/O from the card.
Even if the computer dies the card PLC continues to run as it has it's own power supply.
My 2 cents worth.

Bob, this is what was suggested above. This is an industrially-hardened device and you cannot insert any PC parts into it. Now, since it has an Intel processor and runs Win CE, it may be called a PC. But, for all intents and purposes, this is a PLC as well.

I am not trying to say that is the best solution, but many of the things usually said against using a PC for control applications heve been made non-applicable for gadgets like this one.

lbg_dk said:

Hi all

My company is thinking to change from old style PLc´s to a PC PLC´s

Now mitsubish Q02 and ABB PM571

To Beckhoff CX1030

That are you opinions?

• Do Pc "work" 24/7/365
• Programing style are there big changes (scantimes)
• Other things to be aware of

Are we making a mistake ?

Click to expand...

My experience is this, PC's tend to lock up if something minor goes wrong. We found out why the computer wanted to log on to the internet for an update and we got that fixed but during that time the PC would loose all the setup info. Then came another problem the PC would stop communicating with all of the racks and quit running. After extensive searches I have not found out why yet but I noticed the PC locks up after a 5 minute reboot. We have a controller based on a PLC and a HMI and had no trouble with that. Upon power up the press is ready. We have even tryed to replace the PC multiple times increased memory, Looked for logic flaws, Looked for communication flaws, Even a new hard drive. But the PC is unreliable and the PLC/HMI is reliable.

I have been using Siemens WinAC RTX for about 5 years with no problems. It is a kernal program that runs along side Windows. I use Siemens industrial PC's along with this with no failures. The new multi core processors allow the plc to run on one and windows on the other.

I have looked at the Beckhoff system however I have not used any. I think the software is different but powerful. Very fast scan times and seems to be very powerful.

Keep an open mind.