ClearSCADA is an integrated SCADA host software and comprises three components; the server, a windows client known as ViewX and a web client known as Webx. The server performs all of the functions of the SCADA system including the polling engine, real-time database, alarm processor, historian, reporting and running a web server. The client applications function as the HMI and are connected to the server in a client-server architecture using TCP/IP network.

For high reliability systems, ClearSCADA can be configured in a multitude of redundancy options including dual, triple, disaster recover (DR) sites and remote performance servers for local access. Even LAN/WAN links and connections to remote controller can be configured for redundant paths.

One area that can be a large issue for SCADA software when deployed across WAN links is how to manage the graphic displays. If these reside on the SCADA server then you need a high bandwidth link for reasonable pull-up times. An alternative is to store a local copy of graphics on the remote workstation, but then you face the issue for version management. ClearSCADA native format for graphics is vector based and this is typically 1/20 the size over bitmap graphics, therefore graphics are managed by the server and friendly for low bandwidth communication links.
There are 3 components to ClearSCADA:

1. ClearSCADA Server (point based)
2. ViewX windows client (operator station)
3. Webx client (remote/intermittent user)

It is important to remember that the server manages
the complete system, ie:

* communication drivers
* alarm and event journal
* historic archive (historian)
* configuration database

The clients do not store any part of the SCADA
database locally, hence they are known as
Zero Adminstration Clients (ZAC)