# OPC DA with schneider PLC but have ComSubscription error **URL:** \ **Category:** Ignition\ **Tags:** ignition79\ **Created:** [February 21, 2019, 10:17am UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751 "2019-02-21T10:17:53Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![jean.noel.dotter](https://avatars.discourse-cdn.com/v4/letter/j/c68b51/32.png) [@jean.noel.dotter](https://forum.inductiveautomation.com/u/jean.noel.dotter)\ **Post date:** [February 21, 2019, 10:17am UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/1 "2019-02-21T10:17:53Z")
Dear All, I try to connect to OPC DA with schneider PLC, but have ComSubscription error in log. Local Server seems to be ok. OFS client is able to read write data. Ignition the server status is “connected”, but with OPC Quick Client I am not able to read any tag. I log I can read(see below). Thanks a lot for help… * * * at com.jniwrapper.win32.com.impl.IUnknownImpl.invokeStandardVirtualMethod(SourceFile:762) at com.jniwrapper.win32.com.impl.IUnknownImpl.invokeStandardVirtualMethod(SourceFile:741) at com.jniwrapper.win32.ole.impl.IConnectionPointImpl.advise(SourceFile:93) at com.inductiveautomation.opccom.wrapper.subscriptions.DataChangeDispatcher.advise(DataChangeDispatcher.java:83) at com.inductiveautomation.opccom.wrapper.subscriptions.COMSubscription.oleloop\_updateGroup(COMSubscription.java:775) at com.inductiveautomation.opccom.wrapper.subscriptions.COMSubscription$Connector.internalRun(COMSubscription.java:823) at com.inductiveautomation.opccom.wrapper.OleJob.run(OleJob.java:48) at com.jniwrapper.win32.MessageLoopThread$ThreadSynchronizedAction.run(MessageLoopThread.java:620) at com.jniwrapper.win32.MessageLoopThread$LoopThread.run(MessageLoopThread.java:562) ---
**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:** [February 22, 2019, 5:41pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/2 "2019-02-22T17:41:54Z")
Is there a ‘Caused by’ portion of the log? That usually provides a clue as to what’s going on. ---
**Author:** ![jean.noel.dotter](https://avatars.discourse-cdn.com/v4/letter/j/c68b51/32.png) [@jean.noel.dotter](https://forum.inductiveautomation.com/u/jean.noel.dotter)\ **Post date:** [February 25, 2019, 7:53am UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/3 "2019-02-25T07:53:40Z")
Is there a “best way” to use classic OPC DA with ignition? How to add an item from a server in ignition? In OPC Expert we can see value with correct value, but in ignition we only see “Value null” ![ignition25022019](https://us1.discourse-cdn.com/inductiveautomation/original/2X/5/5aa079bff07602b3686e55af6d93b6477c418e20.png) Sincerely, ---
**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:** [February 25, 2019, 10:56am UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/4 "2019-02-25T10:56:37Z")
From the Knowledgebase: [https://support.inductiveautomation.com/index.php?/Knowledgebase/Article/View/4/2/setting-up-and-troubleshooting-opc-com-connections](https://support.inductiveautomation.com/index.php?/Knowledgebase/Article/View/4/2/setting-up-and-troubleshooting-opc-com-connections) ---
**Author:** ![jean.noel.dotter](https://avatars.discourse-cdn.com/v4/letter/j/c68b51/32.png) [@jean.noel.dotter](https://forum.inductiveautomation.com/u/jean.noel.dotter)\ **Post date:** [February 25, 2019, 2:04pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/5 "2019-02-25T14:04:29Z")
Thanks you for the link. Adding the OPC Core Components x64 had no effect. the settings seems to be fine, but inside the Ignition Designer the Value is always “null”, there is no error, but no data also… any help would be appreciated, ![ignition25022019_2](https://us1.discourse-cdn.com/inductiveautomation/original/2X/5/55ca31b58d37c814ac4a48050d84281bbef227d7.png) ![ignition25022019_2](https://us1.discourse-cdn.com/inductiveautomation/original/2X/b/b466dba9044dc5bac0e8097542132dc02a798507.png) ---
**Author:** ![zxcslo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zxcslo/32/61610_2.png) [@zxcslo](https://forum.inductiveautomation.com/u/zxcslo)\ **Post date:** [February 26, 2019, 10:09am UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/6 "2019-02-26T10:09:10Z")
Right click on the MW0 and int\_siemens tags and select Tag Diagnostics then highlight the Last Error Cause and post the pictures here… That percent sign in tag path is suspicious to me… ---
**Author:** ![jean.noel.dotter](https://avatars.discourse-cdn.com/v4/letter/j/c68b51/32.png) [@jean.noel.dotter](https://forum.inductiveautomation.com/u/jean.noel.dotter)\ **Post date:** [February 26, 2019, 12:50pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/7 "2019-02-26T12:50:23Z")
Thanks you for the answer. the percent sign is ‘typical Schneider’ (see OPC scout tag in the picture). Tag Diagnostics give no error, all is fine, but no data… ![ignition26022019](https://us1.discourse-cdn.com/inductiveautomation/original/2X/b/b03792eeeb1d20764e2a047f9aa68b66f6f30a4d.png) ---
**Author:** ![zxcslo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zxcslo/32/61610_2.png) [@zxcslo](https://forum.inductiveautomation.com/u/zxcslo)\ **Post date:** [February 26, 2019, 1:01pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/8 "2019-02-26T13:01:19Z")
How did you created this MW0 tag in Ignition? Did you write that OPC Item path your self? ---
**Author:** ![jean.noel.dotter](https://avatars.discourse-cdn.com/v4/letter/j/c68b51/32.png) [@jean.noel.dotter](https://forum.inductiveautomation.com/u/jean.noel.dotter)\ **Post date:** [February 26, 2019, 1:17pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/9 "2019-02-26T13:17:10Z")
Yes, the tag has been added by hand (it seems not to be possible to discover OPC DA items). We are able to discover the servers (siemens and Schneider) but not the tag(s). ---
**Author:** ![zxcslo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zxcslo/32/61610_2.png) [@zxcslo](https://forum.inductiveautomation.com/u/zxcslo)\ **Post date:** [February 26, 2019, 1:20pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/10 "2019-02-26T13:20:15Z")
Then it won’t work… You MUST add the tags from OPC Tag browser and drag them to your tags. If OPC Tag browser can’t see the tags in the OPC server, then also adding them by hand doesn’t work. What about Ignition OPC Quick client (at he bottom) on the web configuration page? If you can’t see the tags there, then your connection to the OPC server doesn’t work… ---
**Author:** ![jean.noel.dotter](https://avatars.discourse-cdn.com/v4/letter/j/c68b51/32.png) [@jean.noel.dotter](https://forum.inductiveautomation.com/u/jean.noel.dotter)\ **Post date:** [February 26, 2019, 1:36pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/11 "2019-02-26T13:36:53Z")
If I drag an drop a tag from exposed #specific I get the same behavior (the data is “null”)… ![ignition26022019_DragAndDrop](https://us1.discourse-cdn.com/inductiveautomation/original/2X/0/07085272e9039672a9200d5414e6d92a0cf82a6b.png) ![ignition26022019_QuickClient](https://us1.discourse-cdn.com/inductiveautomation/original/2X/0/011f016c1a865984c3c14cc1fef504d60f31850d.png) ---
**Author:** ![zxcslo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zxcslo/32/61610_2.png) [@zxcslo](https://forum.inductiveautomation.com/u/zxcslo)\ **Post date:** [February 26, 2019, 1:44pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/12 "2019-02-26T13:44:20Z")
Now look at the Logs on the Ignition Status page… There must be some errors… ---
**Author:** ![jean.noel.dotter](https://avatars.discourse-cdn.com/v4/letter/j/c68b51/32.png) [@jean.noel.dotter](https://forum.inductiveautomation.com/u/jean.noel.dotter)\ **Post date:** [February 26, 2019, 2:07pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/13 "2019-02-26T14:07:29Z")
Yes error are displayed but the meaning? ![ignition26022019_logErrors](https://us1.discourse-cdn.com/inductiveautomation/original/2X/a/a30c89ba094123875d7ea1277c1cd0d3ea747289.png) ---
**Author:** ![zxcslo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zxcslo/32/61610_2.png) [@zxcslo](https://forum.inductiveautomation.com/u/zxcslo)\ **Post date:** [February 26, 2019, 2:32pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/14 "2019-02-26T14:32:09Z")
It looks like your Schneider doesn’t support DA3. Show your OPC connection configuration page… ---
**Author:** ![jean.noel.dotter](https://avatars.discourse-cdn.com/v4/letter/j/c68b51/32.png) [@jean.noel.dotter](https://forum.inductiveautomation.com/u/jean.noel.dotter)\ **Post date:** [February 26, 2019, 2:45pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/15 "2019-02-26T14:45:36Z")
The com error says E\_ACCESSDENNIED but where can we check/change this? ![ignition26022019_OPC%20Connection%20page](https://us1.discourse-cdn.com/inductiveautomation/original/2X/0/02ded7f80cbbd55d64575fb6c41a9bddf6ff49a1.png) ---
**Author:** ![zxcslo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zxcslo/32/61610_2.png) [@zxcslo](https://forum.inductiveautomation.com/u/zxcslo)\ **Post date:** [February 26, 2019, 3:18pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/16 "2019-02-26T15:18:02Z")
That means that you DCOM setting in Windows are not set correctly. @JordanCClark gave the link where it is described how to set DCOM… Yes, it is a pain in the a… , I know… been there, done that… DCOM sucks… ---
**Author:** ![jean.noel.dotter](https://avatars.discourse-cdn.com/v4/letter/j/c68b51/32.png) [@jean.noel.dotter](https://forum.inductiveautomation.com/u/jean.noel.dotter)\ **Post date:** [February 26, 2019, 3:26pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/17 "2019-02-26T15:26:51Z")
Thanks a lot for your help: I will try again this settings, but for me I found nothing with “strange settings” in DCOM… Sincerely, ---
**Author:** ![zxcslo](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/zxcslo/32/61610_2.png) [@zxcslo](https://forum.inductiveautomation.com/u/zxcslo)\ **Post date:** [February 26, 2019, 5:30pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/18 "2019-02-26T17:30:00Z")
I suggest looking on google for [OPC DA access denied](http://lmgtfy.com/?q=opc+da+dcom+access+denied). There is also this: [OPC COM](https://docs.inductiveautomation.com/display/DOC79/OPC+COM) inside the Ignition manual. I’ve learned (the hard way) over the years that no two cases are alike involving DCOM. So there are no definite instructions for every case… Last month I spend two days to connect Ignition gateway to 8 old PCs with mainly ABB OPC DA servers. And in the end, most problems were with the DCOM settings on the PCs side. ---
**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:** [February 26, 2019, 6:05pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/19 "2019-02-26T18:05:19Z")
The OPC-COM Tunneler module may help as well. You would have to grab it from the v7.8.5 [download archive](https://inductiveautomation.com/downloads/archive), but it should work for 7.9.x as well. ---
**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\ **Post date:** [February 26, 2019, 6:07pm UTC](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751/20 "2019-02-26T18:07:36Z")
Note: Tunneler will be available again starting with 7.9.11: [https://inductiveautomation.com/downloads/beta](https://inductiveautomation.com/downloads/beta) [Next page](https://forum.inductiveautomation.com/t/opc-da-with-schneider-plc-but-have-comsubscription-error/22751.md?page=2)