RSView Supervisory Edition Installation Guide

7Setting up communicationsThis chapter describes:• what data servers are.• setting up communications.• adding RSLinx ® Enterprise data servers to an application.• setting up communications in RSLinx Enterprise.• adding OPC data servers to an application.• deleting data servers.About data serversA data server provides a route to the physical devices on the network, so you can see thevalues in those devices. Devices can be:• programmable controller values.• OPC ® tags, and their value or status information.• named variables in a ControlLogix ® processor.Types of data serversYou can create two types of data server in an RSView ® Supervisory Edition application:RSLinx Enterprise data servers, and OPC data servers.A single RSView application can contain up to 25 data servers.RSLinx Enterprise data serversRSLinx Enterprise data servers support RSLinx Enterprise, and provide best performancewhen communicating with ControlLogix processors or with large numbers of clients.OPC data serversOPC stands for OLE for Process Control, a protocol used to connect RSView tocommunication devices via vendor-specific OPC servers. RSView supports the OPC-DA2.0 specification. OPC servers provide a way for RSView to retrieve tag values from:• Allen-Bradley ® controller devices, using RSLinx Classic as an OPC server.• third-party controller devices, such as Siemens or Modicon ® , using third-party OPCservers.7 • Placeholder7-1