Interfacing a PLC with a CompactRIO?

[pranjall]

I have a GE Fanuc Versa MAX PLC. I successfully interfaced it with my laptop (Win 7) through LabVIEW using the OPC Server. Now, I want to take the laptop/PC out of the equation and interface the PLC directly to my CompactRIO using OPC UA which happens to be platform independent.

I came across this white paper from NI which talks about creating an OPC UA server application

http://www.ni.com/white-paper/14253/en/ 

But I am not sure how to utilize this information to make a VI that can be deployed on CompactRIO that successfully communicates with the PLC. I have tried it, but it doesn't work. More specifically, I am not sure how can I access the memory variables/register inside the PLC.  

Any leads in this matter shall be deeply appreciated. 

Regards

Pranjal

[dwisti]

I doubt GE Versa Max PLC supports OPC UA directly.  It might support Modbus TCP.

[pranjall]

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@dwisti wrote:

I doubt GE Versa Max PLC supports OPC UA directly. 

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Directly as in? 

I thought OPC is something that is virtually supported by every PLC out there, hence the same must be true for OPC UA. 

/

But I would still ask the same question, as I have a siemens PLC as well and it definitely supports OPC UA. Have you ever done this ?

[df86]

Since you are connecting two pieces of hardware in closed loop, you want to use Modbus to communicate between the two. I'm assuming your PLC has Modbus Over TCP. If so you can configure the settings through any hardware that can act as a Master.

OPC becomes useful if you are trying to communicate between a piece of hardware and a UI, since it reduces the configuration time. But it also adds another layer which can cause issues. 

[pranjall]

Hi df86 

Right now what I am trying to acheive is a system that has a HMI, a CompactRIO and a PLC. The compactRIO does all the data acquisition, analysis and publishes the data on the web and also transmits some data to the HMI that is displayed in a UI. 

The part where I am facing problem is where the CompactRIO and PLC communication happens. I know I can do it through Modbus or I can do the OPC server on the HMI itself and let the HMI talk to the PLC. But that's not what we want to do, idea is to have the CompactRIO talk to the PLC using OPC UA. The reason why we want to stick to the CompactRIO is because of its high reliability. 

Do you have any idea how to do this? Does anyone in this forum has any ideas about this? 

I wonder if this has ever been done befoer.

[df86]

Since OPC is built on top of windows I'm not sure if there is any way to use the OPC server without including a windows PC in the mix.

But here is a white paper on OPC, you should find your answer there.

https://www.ni.com/en/solutions/industrial-machinery/smart-machine-control/introduction-to-opc.html

[dwisti]

I don't know of any major PLC vendor (Siemens, Rockwell, GE) that directly supports OPC UA protocol.  What I mean by "directly" is no middleman OPC server running on a PC to facilitate the connection.  If you know of a PLC that has on-board embedded OPC UA stack, please post a link to it.