-
Re: Value: Value cannot be null. Parameter name: item
Eugene Lee
Apr 9, 2018 4:33 AM
Which data reference is this? Perhaps a screenshot could help.
-
Re: Value: Value cannot be null. Parameter name: item
Its a custom data reference, based off the PI Point data reference
-
Re: Value: Value cannot be null. Parameter name: item
Eugene Lee
Apr 9, 2018 5:33 AM
1 of 1 people found this helpfulWho is the developer of the DR? Are there instances of the DR working properly or it has never worked?
-
-
-
Re: Value: Value cannot be null. Parameter name: item
John Messinger
Apr 10, 2018 1:12 AM
2 of 2 people found this helpfulAlan,
Can I suggest that you try debugging your data reference to pinpoint the source of this error in your code. To debug a custom data reference, I use the following procedure:
1. Compile the plugin.
2. Copy the DLL file to the target directory on the remote machine (\PIPC\AF).
3. Run the RegPlugin.exe on the rebuilt DLL.
4. Start PI System Explorer on your local computer (where you have Visual Studio open)
5. In the plugin project in Visual Studio, from the Debu menu select Debug->Attach to Process. Make sure Managed Code is selected (Select… button). Choose AFExplorer.
6. Set break points at strategic locations in your plugin source (such as GetInputs(), GetValue(), and the methods within your Winform). You could probably set a breakpoint at the beginning of every main method you have written or overridden.
7. In PI System Explorer, select the attribute configuraed with the data reference, click on the Settings button etc - pretty much do the things you would to use your data reference, and then step through each line of code when your breakpoints are hit.
-
Re: Value: Value cannot be null. Parameter name: item
Hi,
we have a similar issue, but it happens on PIVision when trying to use a collection and a filter
