# OPC DA Client Connection changes from Connected to Closed **URL:** \ **Category:** Ignition\ **Tags:** opcua, ignition81\ **Created:** [March 21, 2025, 6:08am UTC](https://forum.inductiveautomation.com/t/opc-da-client-connection-changes-from-connected-to-closed/103995 "2025-03-21T06:08:26Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Mahin\_Ahmad](https://avatars.discourse-cdn.com/v4/letter/m/53a042/32.png) [@Mahin\_Ahmad](https://forum.inductiveautomation.com/u/Mahin_Ahmad)\ **Post date:** [March 21, 2025, 6:08am UTC](https://forum.inductiveautomation.com/t/opc-da-client-connection-changes-from-connected-to-closed/103995/1 "2025-03-21T06:08:26Z")
Hello, I am learning about OPC and setting up OPC Server(DA) in VTScada. (Everything is on local machine) I have setup an VTScada Application as OPC Server. [docs](https://www.vtscada.com/help/Content/D_DataSharing/D_ConfigureAsOPCServer.htm?tocpath=Use%20VTScada%7CTags%20and%20I%252FO%7COther%20Modes%20of%20Communication%7COPC%20Configuration%7COPC%20Classic%20Configuration%7C _____ 4) I can read the tagvalues from another VTScada Application (as opc client) ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/4/b43644ac955a571e50e864da2e0ec2518170f424.png) But from Ignition the OPC connection(DA) flashes from _Connected_ to _Closed_ ![OPC DA Connected to Closed](https://us1.discourse-cdn.com/inductiveautomation/original/3X/3/0/3068b5b563f5ea311b6834e528b0960962949738.gif) But I can discover the tag anyway: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/0/1/01756d5132c7a222b915d6889fa1211ed24829c0.png) But only to get 'not connected' error: ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/c/5/c56091c253322ccdbe7f935c44a33b471b0fd80e.png) ---
**Author:** ![JordanCClark](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jordancclark/32/83362_2.png) [@JordanCClark](https://forum.inductiveautomation.com/u/JordanCClark)\ **Post date:** [March 21, 2025, 6:52pm UTC](https://forum.inductiveautomation.com/t/opc-da-client-connection-changes-from-connected-to-closed/103995/2 "2025-03-21T18:52:25Z")
> [@Mahin\_Ahmad](#): > > OPC Server(DA) That's your issue. Ignition is OPC-UA. You need Ignition's [OPC COM Module](https://inductiveautomation.com/ignition/modules/opc-com). ---
**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:** [March 21, 2025, 6:55pm UTC](https://forum.inductiveautomation.com/t/opc-da-client-connection-changes-from-connected-to-closed/103995/3 "2025-03-21T18:55:08Z")
> [@JordanCClark](#): > > You need That is what the OP is using. ---
**Author:** ![JordanCClark](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jordancclark/32/83362_2.png) [@JordanCClark](https://forum.inductiveautomation.com/u/JordanCClark)\ **Post date:** [March 21, 2025, 7:13pm UTC](https://forum.inductiveautomation.com/t/opc-da-client-connection-changes-from-connected-to-closed/103995/4 "2025-03-21T19:13:19Z")
Apologies, I have trouble seeing the video. Unfortunately, DCOM ~~can be~~ is a real pain to get get working correctly. There's a whitepaper that covers the most common issues, if you haven't already seen it: > **[OPC & DCOM Troubleshooting: Quick Start Guide](https://www.opcti.com/opc-dcom-five-tips.aspx)** > > OPC technology provides an interoperable, reliable, and secure communication platform. To achieve this, OPC relies on a well-configured DCOM infrastructure. ---
**Author:** ![JordanCClark](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jordancclark/32/83362_2.png) [@JordanCClark](https://forum.inductiveautomation.com/u/JordanCClark)\ **Post date:** [March 21, 2025, 7:18pm UTC](https://forum.inductiveautomation.com/t/opc-da-client-connection-changes-from-connected-to-closed/103995/5 "2025-03-21T19:18:12Z")
You may also want to consider the OPC COM Tunneler module. [https://support.inductiveautomation.com/hc/en-us/articles/360047615731-A-Primer-to-the-OPC-COM-Tunneler-Module](https://support.inductiveautomation.com/hc/en-us/articles/360047615731-A-Primer-to-the-OPC-COM-Tunneler-Module) ---
**Author:** ![Mahin\_Ahmad](https://avatars.discourse-cdn.com/v4/letter/m/53a042/32.png) [@Mahin\_Ahmad](https://forum.inductiveautomation.com/u/Mahin_Ahmad)\ **Post date:** [March 22, 2025, 8:48am UTC](https://forum.inductiveautomation.com/t/opc-da-client-connection-changes-from-connected-to-closed/103995/6 "2025-03-22T08:48:37Z")
What I have understood is that the tunneler module helps streamline _makeing remote OPC connections_ by 'wrapping' DA in a OPC-UA simulated device. But first there has to exist a valid connection between the OPC-DA(my vtscada) and local ignition's DA. After that other remote ignition can connect via the additional craeted OPC-UA tunnel, which abstracts the DA and exposes a UA connection... as per my reading... ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/2/0/20d0b2ad25500f66c107d9e628c0c2be870e1536.png) So far what I have done is use the third party **OPCExpert** software to: - read from VTScada DA Server. - Expose a UA Server then using _Ignition UA_ to read the values. - Steps: - After opening OPCExpert for the 1st time, I saw my existing VT DA Server listed. - Then went to Tools \> Servers & Services, Enabled UA Server, did not change the default ports. - Then successfully connected from a remote ignition(vpn) - Image below is: remote ignition \> OPCExpert UA \> VTScada DA - OPCExpert's UA Server can also run as a windows service. Thanks for sharing that OPC Expert article, now i know that 3rd party client softwares connect to VTScada's DA Server **But I'm yet to make it work with Ignition's own OPC-DA connection...** ---
**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:** [March 23, 2025, 4:20pm UTC](https://forum.inductiveautomation.com/t/opc-da-client-connection-changes-from-connected-to-closed/103995/7 "2025-03-23T16:20:31Z")
Does VTscada have an OPC-UA server? That would be a much better option than trying to connect over the dated DA method. Or would it be better to just do direct connections to the end devices with Ignition drivers? What's the end goal? Replacing VTscada?