is it possible to get data from PLC without OPC server?

[Former Member]

Hi,

is it possible to get data from PLC without OPC server?

If possible how?

Thanks.

[jcgood25 · Accepted solution]

In all reality the best way is to have a historian providing a concentration of any and all PLCs in a single harmonized layer, including current, historical, and statistical data access.

Aside from OPC I think a few PLC's out there have embedded light web server capabilities, so a webservice call may be an option, but this would be an exception and not the norm.

[Former Member · Accepted solution]

Hi Jeremy,

Do you mean OPC HDA is enought?

But, Sap MII demo documents say that MII have drivers for PLC connection. I know MII has UDS and PCO components for communications with OPC servers not PLC.

Demo document lists different suppliers PLCs models.It says MII can communicate directly with these devices.

Why is this?

Thanks.

[jcgood25 · Accepted solution]

If it is the document I think you are mentioning, then you could make the same observation about SQL Server, Oracle, and any database for that matter since we require a JDBC driver for connections to databases.

Somehow lost in the documentation metamorphosis (at times by sales) is the notion of 'system' instead of 'device', and the manner in which MII connects to sources of information. You can categorize the non-webservice type maintained connections into JDBC and UDS/PCo (which comprise vendor based API/SDK and standards like OPC).

Bottom line on PLC's, MII is the OPC client and requires an OPC server to create the connection.