# OPC-DA issue?

**URL:** <https://forum.inductiveautomation.com/t/opc-da-issue/3300>\
**Category:** Ignition\
**Created:** [September 19, 2011, 2:10pm UTC](https://forum.inductiveautomation.com/t/opc-da-issue/3300 "2011-09-19T14:10:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![alex.ferrell](https://avatars.discourse-cdn.com/v4/letter/a/958977/32.png) [@alex.ferrell](https://forum.inductiveautomation.com/u/alex.ferrell)\
**Post date:** [September 19, 2011, 2:10pm UTC](https://forum.inductiveautomation.com/t/opc-da-issue/3300/1 "2011-09-19T14:10:00Z")

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I was using RSLinx to connect to a “virtual” PLC with Rockwell Emulate 500. I used the OPC-DA module to allow Ignition to connect to RSLinx as an OPC server. The problem I was having was that data written to a tag in a script with writeToTag would not show up in the tag. I was using a tag change script to parse data from a TCP message and write to my PLC in a string tag. I was able to write data to the string tags from screen components and by manually typing data into the SQLTags viewer. It just would not work with the writeToTag function. I verified my script was actually working. I ended up connecting a ML1100 to my network and changing my tag to point to it using Igntion OPC-UA (same string file address, same program running as emulation) and it worked just fine.

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**Author:** ![Michael.Stofan](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michael.stofan/32/3342_2.png) [@Michael.Stofan](https://forum.inductiveautomation.com/u/Michael.Stofan)\
**Post date:** [September 19, 2011, 6:57pm UTC](https://forum.inductiveautomation.com/t/opc-da-issue/3300/2 "2011-09-19T18:57:29Z")

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Go ahead and attach up a log export (Configuration --\> Console --\> Export Logs) and I’ll see if anything jumps out.

Also, I’ll see if there is anything we could turn on logging-wise to get even more information from the OPC-COM module.