# Modify element of tag array from table cell **URL:** \ **Category:** Ignition\ **Tags:** perspective, scripting\ **Created:** [July 10, 2024, 9:52pm UTC](https://forum.inductiveautomation.com/t/modify-element-of-tag-array-from-table-cell/93041 "2024-07-10T21:52:44Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![simeonw](https://avatars.discourse-cdn.com/v4/letter/s/4da419/32.png) [@simeonw](https://forum.inductiveautomation.com/u/simeonw)\ **Post date:** [July 11, 2024, 1:47am UTC](https://forum.inductiveautomation.com/t/modify-element-of-tag-array-from-table-cell/93041/2 "2024-07-11T01:47:48Z")
I see you have defined the tag data type as a STRING. You might be better to read the tag in as a Document (JSON) data type, as that is how Ignition OPC UA reads in and write to structs. > [@OPC UA struct data type?](https://forum.inductiveautomation.com/t/opc-ua-struct-data-type/26905/2): > > You can take advantage of reading whole structs in OPC UA servers as of Ignition 7.9.12 and 8.0.0. When you bring the tag in you’ll notice Ignition presents a JSON value. The strategy here is a little involved but it works. For each of the UDTs you’ll be subscribing to in the PLC you make a corresponding UDT in Ignition. It should have a “Source” OPC tag member that will correspond to the Node with the struct value in the server and as a result have a JSON value in Ignition. Then for each memb… You are also attempting to write the **data** prop directly to the tag. I imagine this would be a dataset, rather than JSON, based on the function you are using to modify the data in run data. If you look at the **QualityCode** returned by the **system.tag.writeBlocking** , you will likely see that it has failed to write to the tag. Try converting your table dataset back to JSON and then writing that to the tag. As a quick check, you could dump the live tag value in the script console, then also dump the updated value that you are writing back and check whether the structures match. --- _[View the full topic](https://forum.inductiveautomation.com/t/modify-element-of-tag-array-from-table-cell/93041)._