Rif.: OPC PLC Connection

[KimMortensen]

I have setup an OPC server using Kepware to communicate through to a PLC. I am using datasocket.

There is no problem with reading and writing to the OPC server.

Is there a way to check if the connection between the OPC server and the PLC is valid eg. using Datasocket Read? Or is there an other way to check about the data is valid

[Himanshu_Goyal]

Hi Kim,

The value you can get using control value tag to value tag, and the status of tag you can get using state message tag.

[KimMortensen]

I am sorry but I didn't understand what you were trying to tell me. Can you please attach a screendump or try to be more specific

[pincpanter]

Read an item as a variant, then use Get Variant Attribute with attribute name "Quality".

Convert the attribute value to an integer: this is the OPC quality code of the item, a bitmask from which you can extract information about the connection status and other info.

[KimMortensen]

Thanks Pincpanter

Can you tell me which bit is the connection to the PLC?

[pincpanter]

Kepware documentation should give you the answer. Searching the web, I found this document.