# Siemens OPC UDT

**URL:** <https://forum.inductiveautomation.com/t/siemens-opc-udt/38634>\
**Category:** Ignition\
**Created:** [September 13, 2020, 4:27pm UTC](https://forum.inductiveautomation.com/t/siemens-opc-udt/38634 "2020-09-13T16:27:14Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![c.k](https://avatars.discourse-cdn.com/v4/letter/c/7feea3/32.png) [@c.k](https://forum.inductiveautomation.com/u/c.k)\
**Post date:** [September 13, 2020, 4:27pm UTC](https://forum.inductiveautomation.com/t/siemens-opc-udt/38634/1 "2020-09-13T16:27:14Z")

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Hey there,

I’m investigating if Ignition is a platform we can use.  
We mainly use Siemens 1500 plc’s so the Ignition driver is a no-go as it doesn’t support optimized blocks. So that leaves the built in OPC server in the PLC, which i got working.

However when I use the OPC browser and drag the tag in, it makes it as a document type.  
Do i have to make the datatype first, if so how would you do this? I looked up the documentation but could not figure it out. And is it possible to import said UDT somehow?

I’m coming from a WinCC background so the whole thing is quite new for me. Different design philosophy

Tia:  
 ![TiaUDT](https://us1.discourse-cdn.com/inductiveautomation/original/3X/0/c/0c5a6d2598dc2a8cf78138c1c22a5536b3152b56.png)

OPC browser:  
 ![IgnitionUDT](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/8/68b35e664e1820466eae5577c486aec846f83eef.png)

Tag editor:

 ![IgnitionTag](https://us1.discourse-cdn.com/inductiveautomation/original/3X/2/7/274b9c8537914d10378660af1864a7797d2ebb8f.png)

Ignition version is 8.0.16

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<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [September 13, 2020, 4:43pm UTC](https://forum.inductiveautomation.com/t/siemens-opc-udt/38634/2 "2020-09-13T16:43:04Z")

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Ignition maps OPC UA structured datatypes into Documents (JSON), not into any kind of automatically generated Ignition UDT.

The process to map these documents into UDTs is a little involved but it’s described here: [OPC UA struct data type?](http://forum.inductiveautomation.com/t/opc-ua-struct-data-type/26905/2)

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<div class="post-metadata">

**Author:** ![c.k](https://avatars.discourse-cdn.com/v4/letter/c/7feea3/32.png) [@c.k](https://forum.inductiveautomation.com/u/c.k)\
**Post date:** [September 13, 2020, 5:31pm UTC](https://forum.inductiveautomation.com/t/siemens-opc-udt/38634/3 "2020-09-13T17:31:02Z")

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Thanks,

I think i have figured it out. I dragged the items from the opc browser into the UDT and have added the InstaneName in place of the valve number. And for the Struct i used a folder for legibility.