# System OPC Write Value for version 8.1 **URL:** \ **Category:** Ignition\ **Created:** [May 26, 2022, 12:19pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056 "2022-05-26T12:19:56Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![JC\_KO](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jc_ko/32/35061_2.png) [@JC\_KO](https://forum.inductiveautomation.com/u/JC_KO)\ **Post date:** [May 26, 2022, 12:19pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056/1 "2022-05-26T12:19:56Z")
Hi!! I recently upgraded my Ignition edge from version 7.9 to 8.1 as I needed some driver modules from version 8.1. I Imported the tags from my old version to new one and I could not find a way to replicate the “Write back to OPC item” feature from the old version. Does anybody have an idea to how I could modify this for a quick deployment of the project. Thanks! ![5](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/0/d036ca9cd21cd62a9b8f6d1a5382e93a17ee12c0.png) ![6](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/a/bafabeba5c16215efa522ec8e0d43794d60afaa6.png) ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [May 26, 2022, 12:22pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056/2 "2022-05-26T12:22:22Z")
It doesn’t exist. When importing a tag that uses that legacy feature, Ignition creates a tag value change event that replicates the _ **functionality** _. ---
**Author:** ![JC\_KO](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jc_ko/32/35061_2.png) [@JC\_KO](https://forum.inductiveautomation.com/u/JC_KO)\ **Post date:** [May 26, 2022, 12:29pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056/3 "2022-05-26T12:29:23Z")
The legacy value change event seems not working. I’m getting an “Error in Configuration” Is their any workaround to read from and write to OPC tag? thanks! ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [May 26, 2022, 12:31pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056/4 "2022-05-26T12:31:19Z")
I think you have to touch up the values in the script. That script is the only way to do it. Oh, wait! You said **Edge**? Edge won’t run tag events unless you have the Compute module. Talk to IA sales. ---
**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:** [May 26, 2022, 1:04pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056/5 "2022-05-26T13:04:20Z")
If you did a tag import into a fresh install, instead of upgrading or restoring a backup, that OPC UA server name might be incorrect. It’s “Ignition OPC UA Server” by default in 8.x, not “Ignition OPC-UA Server” (no hyphen). ---
**Author:** ![JC\_KO](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jc_ko/32/35061_2.png) [@JC\_KO](https://forum.inductiveautomation.com/u/JC_KO)\ **Post date:** [May 26, 2022, 1:33pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056/6 "2022-05-26T13:33:31Z")
I removed the hyphen as you suggested. I’m only getting a value in a particular expression tag but it doesn’t write the value onto another OPC tag. ---
**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:** [May 26, 2022, 1:37pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056/7 "2022-05-26T13:37:49Z")
I think Phil may be on to something with it requiring Edge Compute… this is ringing a bell but I can’t remember if there’s logic in Ignition to allow this particular script even without compute or if this turned out to be a corner case not supported on upgrade and the fix ended up being “complain to your sales rep” and see if you can get a free compute plugin on your license. ---
**Author:** ![JC\_KO](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jc_ko/32/35061_2.png) [@JC\_KO](https://forum.inductiveautomation.com/u/JC_KO)\ **Post date:** [May 26, 2022, 2:07pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056/8 "2022-05-26T14:07:33Z")
My Ignition Edge does have an Edge Compute plugin on Trial. I’m not familiar with the script that I should be using. ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [May 26, 2022, 2:10pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056/9 "2022-05-26T14:10:44Z")
Add some logging to the beginning of the legacy value change event to see that it is being run at all. Then you can narrow down your troubleshooting. > [@JC\_KO](#): > > I’m not familiar with the script that I should be using. The one the import process wrote for you. ---
**Author:** ![Matrix\_Engineering](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/matrix_engineering/32/19781_2.png) [@Matrix\_Engineering](https://forum.inductiveautomation.com/u/Matrix_Engineering)\ **Post date:** [May 26, 2022, 6:16pm UTC](https://forum.inductiveautomation.com/t/system-opc-write-value-for-version-8-1/60056/10 "2022-05-26T18:16:07Z")
I think with Edge, some functionality doesn’t work even with a 2 hour trial. You may have to contact your account exec and get a 30 day trial.