VTScada Web Services

Part of the Connectivity Package included in the VTScada Development Runtime License.

VTScada Web ServicesWhat is Web Services?

VTScada Web Services SOAP (XML) interface allows third-party business applications to retrieve data from the VTScada Historical Database and much more. Enterprise-level business solutions, such as enterprise resource planning (ERP) systems, can also use VTScada services that you choose to make available from your application.

Applications of Web Services

This may be as simple as developing remote reporting and monitoring applications or as complex as a delivery scheduling system that relies on calculations done in VTScada to predict when material deliveries will be required.
Business applications make requests to VTScada over a network via a Simple Object Access Protocol (SOAP) interface. VTScada interprets these requests, performs the requested actions and responds in the requested format.

How Web Services Works

The Web Services Module provides a means for VTScada to receive Simple Object Access Protocol (SOAP) requests over a network and translate those requests into VTScada procedural requests. The results of these requests can be compiled back into the SOAP message format and sent back to the remote computer.

The WebService module links together a WSDL document, a VTScada Realm, and a set of project-defined VTScada modules. This linkage allows VTScada to accept SOAP messages directed at specific VTScada Realms via the network and translate those messages into procedural requests for VTScada applications. The results of these requests can then be compiled back into SOAP message format and returned to the network entities that made the requests.

Realms can be accessed only by authorized users. Security must be enabled and there must be at least one account with the Internet Client Access privilege.

Each VTScada Realm can expose a single WSDL and connect it to a specific module within a single application. All VTScada modules to be called via that Realm must be direct sub-modules of the connected module, so that the WebService functions can locate them. Subsequent WSDL attachments to the same Realm will supersede existing attachments, not aggregate with them.

Once a Realm is attached to a WSDL it can start accepting SOAP messages immediately and will continue to accept them until the attachment is removed. The individual calls can accept up to 30 parameters each.

Configuring Web Services

Adding VTScada Web Services to your application requires an understanding of XML, SOAP, and VTScada programming techniques.

  • Supports SQL calls from 3rd party apps to VTScada native database
  • Supports SELECT commands and WHERE clauses