Two gateways and tags drag&drop


I would ask you a clarification about tags.

I’ve two gateways that realize an “Hub&Spoke” Cloud architecture. The first one is on the field (Plant GW) and has only the OPC-UA and SQL modules, while the second is fully licensed and it is on the Cloud (Cloud GW). The Plant GW collects data from the field, then push the historical data (Store&Forward) on the remote DB on the cloud. The Cloud GW read the field data from the plant GW (via OPC Connection) and provide all the main features (graphical pages, ecc).

The tags are configured as follow: on the Plant GW I’ve defined the required UDTs and instanciated all the SQL tags. In the UDT I configured also the tag properties (eng unit, etc.).
On the CLoud GW, in order to display the real time data, I opened the OPC browser, then drag&dropped the tag from the plant gateway.

On the cloud gw I noticed two main issues:

  • The UDT structure is lost and then tags are grouped by folders
  • Also the properties, defined in the UDT on the plant gw, are lost

The two issues above imply that I’ve to manually reconfigure every tag of every instance since UDT are no more present… about 8000 tags… I know that I can select multiples tags and reconfigure them in “one shot”, but the structure is quite nested and it is very difficult to do this for every “family”… Another way could be to export the tags and modify the csv/xml file, but I’m afraid that it will be a pain anyway…

Since this is a nightmare, I would ask you how I could reconfigure the (cloud) tags properties in a smarter way (or if I have to modify my approach)…

I hope that my explanation is clear… If not, don’t hesitate to let me know.
Thank you,


I am doing something similar on a smaller scale. I haven’t tried yet, but I think if you go to Configure > OPC-UA > Settings & enable Expose Tag Providers on your Plant GW, then you might be able to get your UDTs. I hope to try it later this week, and I will let you know how it works out.

-Caleb Bohon

I’ve been playing around with tags quite a bit for a project I am working on (using 7.8.1).

Thus far I have found that the most convient way to transport Tags is through export / import.

If your UDTs fail to show up as UDTs, (which has happened to me a couple times.):

  1. Make sure you are exporting all your tags from the originating GW. I highlight the Tags folder to get everything.
  2. Delete your tags on the new server and reimport. It has solved this issue for me at least twice.

Also setting up history and other things can be easier in mass if done with the Exported file.

Hi Caleb,

thank you for your feedback!
I am also currently working with the 7.8.1 and I will try to export/import my tags as you suggest.
My only concern about import/export is to poll twice the devices (from both gateway)… did you do any test about it?

Thank you,

In my situation only one of the GWs is polling the device, the other looks at the the firsts OPC UA server.

Do you have your devices setup on both GWs or just one?

My devices are configured only on one gateway (as in your situation, I have 2 gws, one poll the device while the second should communicate with the first OPC server).


I had a different name for my OPC connection, but other than that my Tag structure was the same. Before I imported I used find and replace to change all OPC Server property values to match the new name.

You might also think about alarms. If you want the alarms to be displayed on clients for both servers you can leave that data in the tags, but if not you can remove it.

Hope it all works out for you!