This option gives users full remote control of the unit via TCP/IP Sockets to allow any aspect of the unit to be modified or queried. This allows complex applications to be created to perform test and measurement functions such as automated testing of routers or other broadcast equipment. PHABRIX products act as a server and listen on a port waiting for incoming requests from clients such as a PC. Using this method of communication the Sx range can provide a variety of information to the control device it is connected to and be controlled in specified areas of the product using the command details included. All visual controls on the product have an associated command. Messages may be sent to ‘set’ or ‘get’ data from a command i.e. if you ‘set’ a value the unit will be configured accordingly and a reply returned and if you ‘get’ a value from the PHABRIX unit it will reply with that value. All messages are acknowledged to increase the security of the interface i.e. closed loop communication. The control structure can be selected as Passive or Active. Passive control allows simple remote control where the host PC is in control and sends commands when it wants to change data or get information. It is this method which is the most popular use for remote control.