Conduit for Industrial Automation: modbus, EthernetIP, OPC-UA

[Eric Tsai]

What are the integration options for the Conduit with PLC’s and industrial networks?

For PLC field bus communications, the use case is to provide sensor data to PLC on an existing field bus. There’s a few different protocol possibilities, and sometimes the physical media isn’t ethernet. For example:

Field Bus Networks

• Modbus/TCP: There’s a node-red node for this. Has anyone had any experience?
• Ethernet/IP: Can we make the conduit appear as a generic ethernet module with read/write buffers for an Allen-Bradley PLC?
• Profibus: On RS-485, is it possible to use the serial mCard for

this?

On the higher level of the industrial network architecture, you might have a SCADA system that wants to get data from the conduit on the ethernet network. So the drivers on the SCADA dictate how the conduit needs to talk to it. There’s a OPC-UA node for node-red. What other options have been tried for the conduit?

I’m not limited to the AEP version, mLinux is OK too.

• This topic was modified 8 years, 5 months ago by Eric Tsai.

[Lawrence Griffiths]

Eric, if your using AEP the only protocol you can use in this context is Modbus.
It’s more of a limitation of Node-RED, than the Conduit. I’ve tried the OPC-UA node a while ago and it was bit buggy. No Profibus but someone has wrapped Ethernet/IP see node-red-contrib-ab https://www.npmjs.com/package/nodepccc

Also Node-RED on the AEP has a restriction on the node.js version which means it runs a old version of Node-RED and some npm modules might require a later version of node.js

[Eric Tsai]

Thanks Lawrence. I was able to install the OPC UA node via npm, but have not tested it against an OPC UA server.

In regards to other industrial protocols, deviceWise publishes a driver list, and they advertise compatibility with the Conduit. Does this driver list apply to mLinux Conduit or is it only for their deviceWise gateway? If the list applies to the Conduit, it seems like an easy way to gain lots of protocols.

https://help.devicewise.com/display/M2MOpen/Device+driver+list

A side question – how do you stop node-red when you’re logged in via ssh, short of killing the process? Is there something like systemd on the AEP conduit? It took many minutes to install the OPC UA node. Wonder if stopping node-red would’ve made a big difference.

[Perico]

Hi Eric and Lawrence,

First of all and unknowing all the rules of the forum I open again this converssation to ask about the topic of it, cause it’s abput what I need information and maybe both participants now has a better vision of it.

I’m working in a similar project than Eric and now I’m looking for information about the best way to send the data of my gateway to a SCADA. As you say I think that there’s only the possibility of Modbus TCP to be sure that it couldn’t cause problems, because it’s a installed node at the gateway Node-Red.

Do you have more information about this or any recomendation?

Thank you,
Roger.

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