# Writing to Edge OPC tag

**URL:** <https://forum.inductiveautomation.com/t/writing-to-edge-opc-tag/105639>\
**Category:** Ignition\
**Created:** [April 28, 2025, 4:41pm UTC](https://forum.inductiveautomation.com/t/writing-to-edge-opc-tag/105639 "2025-04-28T16:41:58Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![gfeiten](https://avatars.discourse-cdn.com/v4/letter/g/cdc98d/32.png) [@gfeiten](https://forum.inductiveautomation.com/u/gfeiten)\
**Post date:** [April 28, 2025, 4:41pm UTC](https://forum.inductiveautomation.com/t/writing-to-edge-opc-tag/105639/1 "2025-04-28T16:41:58Z")

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I am trying to write to a PLC tag from the main gateway (v 8.1.45) to a tag on an edge device (IIot v 8.1.45). I am using a system.tag.write(). I am getting the error: Bad\_AccessDenied. Is there a configuration change I need to make on the edge device to allow writes?

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**Author:** ![gfeiten](https://avatars.discourse-cdn.com/v4/letter/g/cdc98d/32.png) [@gfeiten](https://forum.inductiveautomation.com/u/gfeiten)\
**Post date:** [April 28, 2025, 6:57pm UTC](https://forum.inductiveautomation.com/t/writing-to-edge-opc-tag/105639/2 "2025-04-28T18:57:00Z")

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I found the answer in this post:

> [@Tag write to edge gateway fails](https://forum.inductiveautomation.com/t/tag-write-to-edge-gateway-fails/78091):
>
> Edge Gateway serving tags to a central server. I can see all of the tags in a perspective session, can see them from the server's designer. If I try to write to a property from anywhere but the edge gateway designer, the write fails. The error only says Bad\_AccessDenied. No other data and no entry in a log that I can find to provide me any other information. [image] I have no entries in the Tag Read, Tag Write, and Tag Editing Permissions boxes in the Gateway Configuration. I wanted to get al…

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**Author:** ![michael.flagler](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michael.flagler/32/26272_2.png) [@michael.flagler](https://forum.inductiveautomation.com/u/michael.flagler)\
**Post date:** [April 28, 2025, 7:47pm UTC](https://forum.inductiveautomation.com/t/writing-to-edge-opc-tag/105639/3 "2025-04-28T19:47:10Z")

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You also need to change to using the `system.tag.writeBlocking` or `system.tag.writeAsync` functions as `system.tag.write` is a deprecated function.