This scenario demonstrates a method of connecting CitectSCADA to a number of devices that are distributed across several sites over a wide geographical area.
Instead of attempting to connect devices directly via a remote connection, an I/O Server is placed at each site, enabling communication to be managed within the system.
This model is also useful in plants that contain devices with a serial port or limited communications capabilities. By placing I/O Servers on the factory floor to interface with these devices, you can optimize communications on slow or low-bandwidth networks and improve overall performance.
Despite the geographical distribution of I/O Servers across many sites, this type of system can be configured as a single cluster system, as a cluster is able to support many I/O Servers.
The diagram below demonstrates how to approach the deployment of this type of system across the server machines using a single cluster.
A second cluster will only become necessary if your project requirements call for more than one redundant pair of alarms, trends or reports servers.