B&R PLCs - some help and avice please?

OK, here's the story.

I'd never heard of B&R, but we install our product next to some kit which apparently has a B&R PLC inside.

Our product has serial ports, an RS485 port, and an Ethernet port on it. It currently implements Modbus RTU master, and could probably be fixed to do Modbus TCP easily.

There are data values we would really, really, like to have, which the PLC knows.

The manufacturers of the equipment don't want anyone to go poking around in their PLC, and will not help.

Someone else HAS done this. I've talked to them, but they haven't as yet made any offer to share/sell the capability to us.

However they did say that the work they have done involves accessing the PLC using OPC.

I, personally know zilch about OPC. Our unit incluides a Linux computer, so I guess I can probably obtain something to run under Linux and start a conversation with the PLC.

Questions then...

1. Does anyone think I've missed any points in my understanding?
2. Can anyone say for sure what form of hardware interface on the B&R the OPC link will be operating over?
3. Does anyone know of a commercial product which could be stuck in between our kit and the B&R to provide a modbus slave to OPC link, thus getting me where I want to go ussing money rather than work?
3. Is anyone an expert on these PLCs, and based in/near the UK, and maybe interested in looking into it for us?
4. Can anyone point me to a "noddy's guide to OPC" which can make me less ignorant?
5. Does anyone know anything about sourcing the required Linux s/w to mimplement the OPC function?

Thanks for any/all help

David

actually - I'm assuming we have to use OPC, becasue that's what the other people did.
I'm equally open to any other method of getting inside the PLC that works!!!

I have had dealings with B&R before, they are weird little beasts, a cross between a PLC and a PC, what sort of equipment is it on ?

Its not used that much apart from a few industries in the UK that i know of

Er, I am a bit nervous about quoting the exact kit it's in in the open

happy to do so via email - I'll try a private message on here, and if nowt arrives, can you email me a one-liner at from_plctalk@dexdyne dot com please?

I think that without the symbols from the PLC project you are stuck.
How do you know which adresses to access ?

If the original manufacturer dont want to open up the PLC for you, you should evaluate your options.
Can you ask the vendor to create the appliation you want, rather than that you make it yourself ?
Can you threaten him (in a polite decent way of course) ? Like "we shall not purchase any further machines from you".
Can you hook the vendor up on something in the contract that can be interpreted as that you should have access to the PLC ?

Regarding the hardware, then the serial port is plain RS232 and the Ethernet port is standard Ethernet.
For OPC access you would have to purchase the OPC server from B&R, and then let that take care of the actual protocol on serial or ethernet.

Ok will look out for it, i am a little it the same way too

i used to work for a company that used B&R, i didnt use B&R but our other site did use B&R (long story !!)

i might be able to point you in the right direction on getting some help, have you tried B&R UK ?

At the very least the manufacturer should be able to give you a list of variables that you want to pick up from OPC, assuming B&R have an OPC connection which i think think from memory they have

Aha, linux. Missed that part.
I have heard something about a project to implement OPC on Linux, but I think it is going nowhere (havent heard otherwise).
Your best bet to connect from Linux to the B&R PLC is Modbus RTU via serial. But then the PLC has to be setup for Modbus RTU, and that you cannot do without the cooperation of the original vendor.

Jesper,

yes we have a Linux PC, though I suppose I could stick in a small embedded PC to interface between the Linux m/c and the PLC if I had to. It's not my preference, but what the hey.

I think the other guys who did it just conducted a register trawl, looking for registers that matched the "oil temp" on the front panel and so on. I could be wrong, and if you absolutely need the text name, maybe they did have some inside info.

SO is the B&R PLC an OPC client.... and we have to run an external server... or does the PLC contain a server... or does it contain some proprietory stuff that talks rugglish to the B&R s/w which then presents it as a server.... as you can see I need to do more research.



David

How old is the machine? Can you describe the B&R components you see? It could be the older B&R which uses the program called ProSys or it could be the newer version which uses Automation Studio. Also if you could tell me more about the application such as does it have a HMI? Is the values you are looking to get also displayed on the HMI? Depending on the model of the PLC it might be a lot easier than you think. If you feel PM me. Have a nice day.

dexdyne said:

OK, here's the story.

I'd never heard of B&R, but we install our product next to some kit which apparently has a B&R PLC inside.

Our product has serial ports, an RS485 port, and an Ethernet port on it. It currently implements Modbus RTU master, and could probably be fixed to do Modbus TCP easily.

There are data values we would really, really, like to have, which the PLC knows.

The manufacturers of the equipment don't want anyone to go poking around in their PLC, and will not help.

Someone else HAS done this. I've talked to them, but they haven't as yet made any offer to share/sell the capability to us.

However they did say that the work they have done involves accessing the PLC using OPC.

I, personally know zilch about OPC. Our unit incluides a Linux computer, so I guess I can probably obtain something to run under Linux and start a conversation with the PLC.

Questions then...

1. Does anyone think I've missed any points in my understanding?
2. Can anyone say for sure what form of hardware interface on the B&R the OPC link will be operating over?
3. Does anyone know of a commercial product which could be stuck in between our kit and the B&R to provide a modbus slave to OPC link, thus getting me where I want to go ussing money rather than work?
3. Is anyone an expert on these PLCs, and based in/near the UK, and maybe interested in looking into it for us?
4. Can anyone point me to a "noddy's guide to OPC" which can make me less ignorant?
5. Does anyone know anything about sourcing the required Linux s/w to mimplement the OPC function?

Thanks for any/all help

David

Click to expand...

A short intro to OPC:

OPC is a standardised PC software interface for exchanging data with field devices. It is based on COM and DCOM and is therfore exclusive to the Windows platform. OPC XML should open up for further ways to connect, but I still dont think it will help much for your linux project.

An OPC server is a software package on a PC that talks with the field devices. An OPC server provides (serves) a connection to other software packages.
There is an OPC server for the B&R PLC that connects to B&R via B&Rs proprietary serial and ethernet protocols.

An OPC client is a software package on a PC that uses the connection provided by the OPC server. Typical OPC clients are SCADA/HMI software packages and database storage and retrieval software packages.

Like I said before, for Linux there are Modbus RTU libraries (and probably also Modbus TCP libraries), but the problem is that I dont think you can use these protocols without the B&R PLC being setup to talk Modbus RTU or Modbus TCP. So you cannot do this without the original vendor.

> A short intro to OPC:

For which much thanks

> OPC is a standardised PC software interface for exchanging data with
> field devices.
> It is based on COM and DCOM and is therfore exclusive to the Windows
> platform.

Oh well, OK.

> OPC XML should open up for further ways to connect, but I still dont
> think it will help much for your linux project.

Tell me if you think OPC XML changes anything below.

OK - but if I had to stick an embedded PC with a copy of embedded XP in a little box next to the unit I could do that.

> An OPC server is a software package on a PC that talks with the field
> devices. An OPC server provides (serves) a connection to other
> software packages.
> There is an OPC server for the B&R PLC that connects to B&R via B&Rs
> proprietary serial and ethernet protocols.

Oh blow it. So the B&R PLC has an alway-available protocol which it is prepared to use to interact with a proprietary piece of B&R s/w running on a 'nearby' PC, but I can't "emulate" that link because, well, because it's proprietary.

> An OPC client is a software package on a PC that uses the connection
> provided by the OPC server. Typical OPC clients are SCADA/HMI
> software packages and database storage and retrieval software
> packages.

Ok... so in principle one could combine the B&R OPC server with an OPC client running on the same PCB, and have the OPC client offer up a modbus-TCP slave ( for instance ) interface, so my existing kit could interrogate it. That's a heck of a lot of infrastructiure for a simple task, but it could function?

> Like I said before, for Linux there are Modbus RTU libraries (and
> probably also Modbus TCP libraries), but the problem is that I dont
> think you can use these protocols without the B&R PLC being setup to
> talk Modbus RTU or Modbus TCP. So you cannot do this without the
> original vendor.

We believe that all to be true. We have working RTU master code running, and gather TCP is just a question of encapsulating it.


Many thanks for that clarification.

David

> How old is the machine? Can you describe the B&R components you see?
> It could be the older B&R which uses the program called ProSys or it
> could be the newer version which uses Automation Studio.

The equipment will probably all be < 36 months old, and if necessary I could only provide the feature for more recent models.

I think it's a B&R 2005

> Also if you could tell me more about the application such as does it
> have a HMI? Is the values you are looking to get also displayed on
> the HMI? Depending on the model of the PLC it might be a lot easier
> than you think.

Yes it has an HMI. I know it presents a PCAnywhere interface, so I guess it's a PC-based HMI.
Yes I think you can access all the required info through that interface.

I assume the HMI doesn't already run the OPC server s/w..... but I could be wrong about that

> If you feel PM me.

I've done so with more details.

> Have a nice day.

I'm very grateful for your, and all other advice here.

David