# OPC Tag Write Permission Denied to Siemens OPC UA Server

**URL:** <https://forum.inductiveautomation.com/t/opc-tag-write-permission-denied-to-siemens-opc-ua-server/88286>\
**Category:** Ignition\
**Tags:** perspective\
**Created:** [April 3, 2024, 1:35pm UTC](https://forum.inductiveautomation.com/t/opc-tag-write-permission-denied-to-siemens-opc-ua-server/88286 "2024-04-03T13:35:29Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Aditya\_Kulkarni](https://avatars.discourse-cdn.com/v4/letter/a/898d66/32.png) [@Aditya\_Kulkarni](https://forum.inductiveautomation.com/u/Aditya_Kulkarni)\
**Post date:** [April 3, 2024, 1:35pm UTC](https://forum.inductiveautomation.com/t/opc-tag-write-permission-denied-to-siemens-opc-ua-server/88286/1 "2024-04-03T13:35:29Z")

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Hello All,

I am using Ignition V8.1.19 and configured OPC client connection with Siemens Sinumerik One PLC OPC-UA server. This is basically the S7-1500 PLC.

I have transaction groups to update the data in SQL Database .  
I am able to read OPC tags and storing them in Database based on trigger value.  
But while writing back the results i am getting error .  
( Error writing to TransactionOk.value: Bad\_AccessDenied("User does not have permission to perform the requested operation.") )

 ![Write_Fail_Error](https://us1.discourse-cdn.com/inductiveautomation/original/3X/e/e/eedba2a083c14ed2442a4d193a04fc34e9c36c76.jpeg)

What permission its asking about and for which user.

We use OpcUaClient as a user name while creating OPC-Client connection.

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<div class="post-metadata">

**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:** [April 3, 2024, 1:51pm UTC](https://forum.inductiveautomation.com/t/opc-tag-write-permission-denied-to-siemens-opc-ua-server/88286/2 "2024-04-03T13:51:13Z")

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Seems to obviously be a Siemens configuration issue. Are you sure your user has write privileges in the Siemens? Or is writing to nodes that aren't always read-only?

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**Author:** ![Ahiero](https://avatars.discourse-cdn.com/v4/letter/a/a698b9/32.png) [@Ahiero](https://forum.inductiveautomation.com/u/Ahiero)\
**Post date:** [January 21, 2025, 9:55pm UTC](https://forum.inductiveautomation.com/t/opc-tag-write-permission-denied-to-siemens-opc-ua-server/88286/3 "2025-01-21T21:55:39Z")

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The Sunumerik systems default to read only and require an OPC Admin account to set the user permissions. This is done with an OPC method call. The OPC-UA user has permission to grant their own permission set to write over all areas. Check the Siemens manuals on the OPC-UA server.