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An OPC operation failure with error code 0x800401F3

08 Jan 2020 07:32 #8120 by support
I am not sure if my recent reply went into the system, so briefly repeating: Can you please explain/elaborate on "Using a server simulator, the c# code has proven to be functional"? - I have not understood this part.

Also, have you tried some other OPC client, and what were the results?

As to the computer name, "localhost" or the machine should work for the local computer, but the best choice is to use an empty string.

Best regards

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07 Jan 2020 16:43 #8116 by Ronald B. Livesay
This is the culprit: object x = _client.ReadItemValue( _Machine, _Server, _Tag );
private readonly EasyDAClient _client = new EasyDAClient();
using OpcLabs.EasyOpc.DataAccess;

Windows 10, Visual Studio Enterprise 2019, Winforms, c#

Server is Kepware (Kepware.KEPServerEX.V6) running on the same computer

Searches at OPC Labs for the error code (0x800401F3) have not proven very helpful

The Exception is:
An OPC operation failure with error code -2147221005 (0x800401F3) occurred, originating from 'OpcLabs.EasyOpcRaw.DataAccess.RawEasyDAClient' and with depth of 1. The inner exception contains details about the problem.

Inner Exception is:
Invalid class string + The client method called was 'ReadMultipleItemValues'.

In the call to ReadItemValue:
_Machine has been various values {e.g. "","localhost", actual machine name, etc.}
_Server is always Kepware.KEPServerEX.V6
_Tag is a tag known to exist in the Kepware server (e.g. XT1-P2)

Kepware is running fine with the Kepware tools showing usual stuff

Using a server simulator, the c# code has proven to be functional

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