ProtoLink developed a pair of data-driven web applications to present gas measurement data retrieved from relational databases and OPC servers through a browser interface.
Our client, a leading manufacturer of gas measurement devices, desired an application which could interoperate with existing relational databases and OPC servers to present historical and real-time data over intranets or the Internet. The application architecture needed to be flexible enough to suit the needs of two disparate customer groups. The first customer type is the independent operator willing to pay for a subscription service, wherein our client collects measurement data and hosts the application on behalf of the customer. The second customer type is the large company willing to gather its own measurement data and self-host the application.
ProtoLink addressed these needs by developing a pair of web applications using Microsoft .NET technologies, including C#, ASP.NET, and ADO.NET. The first application allows administrators to control what data is presented and which operations can be performed on that data. Authorized administrators accomplish this by defining a navigational hierarchy along with associated reports and trends. Administrators are also responsible for configuring database and OPC server locations, security roles, and users.
The second application allows users to view data in a tree and list format. After logging into the system, a given user is associated with a security role. This role governs the appearance of the tree and the set of available operations accessible via the tree from context-sensitive menus. The types of operations available include viewing contextually appropriate reports and trends and launching custom web pages. By leveraging HTTP and the Simple Object Access Protocol (SOAP), the second application is also able to display values from OPC XML-DA servers and write values to specific OPC items.