There are many important uses of TCP/IP encapsulation in SCADA applications, but two of the most important are those such as a Web Tunneling Gateway, and communication driver encapsulation. Both serve very necessary purposes in remote and wireless SCADA applications.
Web Tunneling Gateway
The web tunneling gateway is a form of TCP/IP encapsulation that is firewall friendly, allowing users to pass communications between a local server and the internet to a web thin client. During this process, a firewall can block unknown protocols, but using the Web Tunneling Gateway, the communications can be encapsulated in the firewall friendly HTTP (usually on Port 80) and HTTPS protocols. The HTTPS encapsulation provides more security for users through SSL and the IIS web server. The web tunneling gateway is a web service through IIS.
Communication Driver Encapsulation
Communication driver encapsulation is a different use of TCP/IP encapsulation in the InduSoft Web Studio SCADA software. For SCADA software to communicate with an RTU or PLC, a physical layer protocol is required, the most common being Ethernet and Serial RS-232. However, these physical layers have limitations, such at the 15 meter (50 feet) distance limitation of a RS-232 Serial cable. With InduSoft Web Studio, a converter can be used to connect to a remote device. All serial drivers in InduSoft Web Studio can be encapsulated over TCP/IP, UDP/IP or modem, making it easy to send the information wirelessly to a converter connected to the RTU, PLC, or Controller.