# Access UDT parameter in script

**URL:** <https://forum.inductiveautomation.com/t/access-udt-parameter-in-script/27824>\
**Category:** Ignition\
**Created:** [August 28, 2019, 7:55am UTC](https://forum.inductiveautomation.com/t/access-udt-parameter-in-script/27824 "2019-08-28T07:55:45Z")\
**Posts on this page:** 1\
**Showing post:** 13

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**Author:** ![zxcslo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zxcslo/32/61610_2.png) [@zxcslo](https://forum.inductiveautomation.com/u/zxcslo)\
**Post date:** [August 30, 2019, 3:07pm UTC](https://forum.inductiveautomation.com/t/access-udt-parameter-in-script/27824/13 "2019-08-30T15:07:00Z")

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Well... then I'm 'lost'...  
In my case, when I drag from OPC browser the UDT (struct) tag from my S7-1500 OPC UA server, that tag is Unicode string type (JSON). You obviously get Document type.

 ![Capture](https://us1.discourse-cdn.com/inductiveautomation/original/2X/3/3d7363b150f0f14cf40c506cababdc9a5a8dc1bb.png)  
I'm using v7.9.12. You're using v8.  
In v8 system.tag.read is deprecated (but it'll still work, for backward compatibility). The new function is [system.tag.readAsync](https://docs.inductiveautomation.com/display/DOC80/system.tag.readAsync).  
Maybe system.tag.read was changed in v8...??? Maybe @Kevin.Herron can explain?

EDIT: I read the other post it again and it seems that, because tag system is completely changed in v8:

> [@jsonSet workaround in script](https://forum.inductiveautomation.com/t/jsonset-workaround-in-script/27560/2):
>
> edit: the Document object in our tag system might be a mutable GSON object and not a String… I’ll have to look at this in a bit when I get the office.

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