Siemens UDT vs AB

I'm working in 8.1.33 maker edition
Ive worked with AB and Ignition UDTs and they work great. Everything is mapped well from the PLC to the Tags when made properly. I specify my devices in AB: P101. for example In Ignition its parameter is mapped like this. Device Type-P, Device_Tag-101.

After this in ignition its mapped to where you drop the name and device and my pre-built template is populated.

I'm trying to make this work the same way with a siemens s7-1200. Except its not. I built a FB in TIA similar to what AB calls a D2SD, This will be nested inside my FC block so I can add Global tags to make the block work.

What I have done in ignition is make a UDT from the Siemens D2SD FB, This is fine becuase it will be re-used over and over again. I then make another UDT with the "D2SD" as its parent. The problem im facing is making my FC re-usable. Its not like an AB PLC were I just drop the name in. Im using OPC addresses that are all different. i.e-i=76, i=23. I can make the value of the tag parameterized, but with OPC, all the numbers change. Is there a way to make this work without so much work? Using a UDT isnt worth the time with siemens and OPC if this is the case.


I don't know how precisely Siemens does the OPC-UA paths, but you shouldnt need to be using the i= part of the path, I believe that you should be able to use strings much like you would with an AB path on the Ignition OPC-UA server.
s= is the string identifier, you would have to play around with the path to work out how Siemens sets up the node structure on the Siemens OPC server. You might be able to see the structure just fine when you click browse for the tags in designer.
I have also used UaExpert "UA Reference Client" - Unified Automation to gain much better insight into structures and paths and node IDs. All paths that work in UaExpert work in the Ignition Client as far as I have tested.
UaExpert also exposes the OPC-UA methods you can call to run functions on the server.
I would run a quick test on this, but I don't have a Siemens PLC handy with the OPC license.

Also, I have seen a bunch of information that indicates that UDTs in Siemens can be pulled as the only OPC item tag (maybe a document datatype) , and all the data structures underneath can be built as derived tags from that one structure received, which apparently is much faster when you scale. This way you only have to parameterise the Siemens UDT address, and the Ignition UDT automatically uses the data.

The attatched is how searching for the raw tag looks through ignition. I do use Unified to search through my OPC on the PLC. There is a lot more options on Unified, it doesnt seem like I get those options through the Opc on Ignition. I can delcare the NS, the OPC Server, and the Id. Unless im not seeing someting correctly? I did try to use the BrowseName from Unified. It errors out and says its looking for a namespace id number.

The OPC UA interface on a 1200 is in my opinion useless. They don't expose the "Simatic Interface", which is how you can read all the DB etc from a 1500.

Until they do, you are stuck with addressing by id, and there's no rhyme or reason to where that comes from.

If they fix OPC UA on the 1200, to expose the Simatic Interface, they might sell a lot fewer 1500s