I'm writing up a proposal for a client... they have a Kepware OPC server that has a MS-SQL database back end that is fed data from their Siemens control system...
The client has said that he would like us to look at querying the MS-SQL database directly for all the values for the system... His intention is to replicate the SQL DB from their secure network to a DMZ for us to talk to - providing better isolation given this system will be exposed to the internet.
- Is there any limitations or scalability issues with query for thousands of values via a database connection?
- Does Mango keep a connection alive per data source and issue all the defined queries across that link, or does it connect, authenticate, query, disconnect?
Is there a better way to query an OPC server for this kind of data?