WAP technology opens up PLC communications capabilities
Schneider Electric’s ‘Transparent Factory’ concept uses Ethernet
TCP/IP and the Internet to link groups of PLCs and enable closer
interaction between factory control and business systems. The latest
development is WAP mobile telephone access to these Internet enabled
PLCs, allowing remote control and monitoring via a digital cell ‘phone
link. Instead of accessing a SCADA system, users simply dial into a WAP
gateway, which connects them to the web server in the PLC once their
identity has be authenticated. As well as two-way communication between
PLCs and the mobile telephone, it is also possible for the control system
to raise alerts in the event of equipment failure or service disruption.
this is achieved either by sending e-mail or using the simpler mobile
telephone short messaging service (SMS), which carries messages of up to
160 characters.