Soft PLC or Hard PLC?

[JesperMP]

S7-mEC anyone ?

(since the tread has already been resurrected)
This is out of pure interest into the matter.

Does anyone use the socalled Siemens S7-mEC system ?
Or consider to use it ?
Or even know it exists ?
http://www.automation.siemens.com/s...e/embedded/s7-modular-embedded-controller.htm

It is an IPC in S7-300 format, and you can attach S7-300 modules (It looks like M7-300 has been resurrected).
For 3000 Euro you get a EC31 CPU with a Core Duo 1.2 GHz Processor, WinXP embedded and WinAC RTX.

And what about Microbox 427B ?
Anyone using it, or thinking about using it, or even know it exists ?

Personally, I look at Beckhoff with interest. However it is unthinkable that my company would consider anything else than the biggest automation players (= Siemens and AB).

 

[CharlesM]

Does anyone use the socalled Siemens S7-mEC system ?
Or consider to use it ?
Or even know it exists ?

I have not used it but I think it will be the next big thing.

And what about Microbox 427B ?
Anyone using it, or thinking about using it, or even know it exists ?

I would love to try one but I want to give it a little more time. It seems like they have a lot of updates. When the updates slow down I will know they got all the bugs out. I think these products will be the future. They still need to improve the memory so you can get rid of the hard drive and still have room to work. I think as new memory comes out these will really take off.

Personally, I look at Beckhoff with interest. However it is unthinkable that my company would consider anything else than the biggest automation players (= Siemens and AB).

I took several months and looked hard at Beckoff. They gave me several demo's of the software and hardware. I think if I was starting from scratch it would be hard not to go with Beckoff. On the other hand machines sell better with a Siemens or AB tag on the front.

 

[Jeebs]

Damn, that EC31 looks HUGE.

The 427B Microbox is small, but heavy lil thing. Not sure what it can do since I never really used it. But do remember it's remote I/O only. Profibus/net are both supported.....

If I really, really, really have to install a PC instead of a PLC, I'd take Siemens Panel PC's, 600 or higher series and use a S7 41x 2 PCI with extended PS and external 24V power supply. This way ol Bill's windows can crash all it wants, my Controller will happely keep working on.

We have a few embedded PC's/SoftPLC's and getting a call at 4am telling you they have a system32.dll error is not my way of starting bright and early.

I think each and every SoftPLC/embedded PC we have has died at least once so far. Yet we have PLC's that haven't been touched since commisioning.

 

[JesperMP]

We have a few embedded PC's/SoftPLC's and getting a call at 4am telling you they have a system32.dll error is not my way of starting bright and early.
I think each and every SoftPLC/embedded PC we have has died at least once so far.

Out of interest: What were the soft-PLCs that you have experienced these problems ? What was the hardware ?

 

[JesperMP]

Damn, that EC31 looks HUGE.

Sizewise, the EC31 is 'only' as big as a 319.
Performancewise, the EC31 should be much faster than a 319.
Pricewise, the EC31 is significantly cheaper than a 319. OK, it is not easy to compare, the EC31 does not have DP ports, but in stead it has more ethernet ports.

Indeed, if this new platform takes off, we can hope that smaller and more affordable CPUs will become available. Maybe with Intel Atom processor like the announced Beckhoff CX5000.

 

[Jon R]

I have used Beckhoff on a recent project using a combination of their PLC and running TwinCAT on a PC. This was mainly due to the fact that the PLCs were required to keep running in the event of PC failure or restart, which doesn't happen with the BK modules.

The PC has very little installed on it and is one of Beckhoffs own units, with their own OEM version of XP Pro. TwinCAT just talks to the units to get data out and pass information around.

In all the testing I haven't seen BSOD once and the CPU usage is low.

As for locking down the PC, the guards can only access the HMI screen and have no permissions to get to the main OS, and the only programs installed are the neccesary ones.

I have been very impressed with the whole package. The only thing I would like would be TwinCAT ported to Linux.

Jon.

 

[Archie]

I took several months and looked hard at Beckoff. They gave me several demo's of the software and hardware. I think if I was starting from scratch it would be hard not to go with Beckoff. On the other hand machines sell better with a Siemens or AB tag on the front.

I recently completed a project that involved upgrading a system that used a DOS PC running a Clipper program to controll the database and user interaction and serveral SLC500 processors to control the IO. When it came to debugging, the Clipper program was a nightmare, not counting the fact that the vendor would not give out the source code.

The system used a lot of database interaction and was too complicated to incorporate everything in the SLC. My solution was to use a Beckhoff CX1020 to replace the DOS PC and TwinCAT to replace the Clipper program. When it comes to debugging, you can now go online with TwinCAT and the SLCs to see the whole process.

I implemented the SLC500 protocol (DF1) in TwinCAT and was able to read and write the SLCs data memory from a TwinCAT function block.

After it was all complete, the system was able to take advantage of the Beckhoff system and yet still carried the familiar AB hardware.

 

[BobB]

Omron have a PCI card that is actually a PLC. It runs on 24VDC and has all I/O available as remotes. Even if the PC dies or Windows has one of it's normal heart attacks, the PLC keeps running. I believe you can even take the card out of the PC and the PLC keeps running.

That would be my choice over relying on a PC anyday if I ever considered using a PC rather than a conventional PLC system.

 

[kamenges]

BobB, that's just a hard PLC with a PCI data interface. So your position is hard PLC or nothing, which I'm fine with by the way. I don't necesarily agree but I'm fine with it.

A soft PLC is really about price/performance ratio. In most cases you get better than plc performance at a lesser price. But you have the reliability question, which may or may not be valid.

I wouldn't necessarily run screaming away from a soft plc. But I don't work in a world where I need soft PLC performance so it's hard for me to justify it given the price of the stuff I use now.

Keith