Using the OPCUA Toolkit to duplicate NI OPC Servers

[ColinMA]

I'm currently trying to see if it is possible to duplicate the work done in NI OPC Servers using the OPCUA toolkit. Specifically, I have an Allen-Bradley Controllogix 5500 PLC that we currently connect to using the NI OPC Servers software. I want to move away from using this and try using the OPC UA API I have in LV2015 SP1 to make a client VI to connect and read tags from the PLC. I have not been successful thus far in my endeavors and would appreciate any help someone could provide. If anyone has an example of how they achieved a connection to a PLC using the OPCUA toolkit, that would help me a lot.

[ThreeLions]

Hi,

NI strongly recommends using LabVIEW OPC UA 2017 Toolkit. The new toolkit separates the OPC UA functionality from DSC or LV RT module. Also, the stack of the toolkit has been changed from OPC Foundation to UaExpert. This makes many errors and defects have been fixed natively.

* For using the toolkit, you should upgrade your LabVIEW to 2017 version.

Thanks!

[ColinMA]

So I have been doing some more research on this and pulled in a PLC expert, and discovered that the NI OPC Servers software pulls some tricks in the background. All my information is coming from the following: ftp://ftp.ni.com/pub/branches/northern_region/nidays2008/acces_data_industrial_device_lv.pdf.

It looks like the NI OPC Servers fakes an OPC server on the computer running labview, and updates this server with information it gets from the PLC using the EtherNet/IP protocol. Labview creates a client to this OPC server to get the data in. This led to a lot of my confusion as I assumed that the PLC was hosting the OPC server and that I could use the OPCUA API to connect to it, but that is not the case. It appears that NI has a EtherNet/IP module (http://sine.ni.com/nips/cds/view/p/lang/en/nid/209676) that may allow me to skip using OPCUA all together. I'm currently trying to get a demo copy and I will update this post as I learn more.