Truck Data Link E7 is a standardized interface between the electronics in the tank truck and a portable computer (PDA, personal digital assistant). Maintaining this interface allows the operators of tank trucks to use different brands and expansion modules in the tank truck and to communicate with the host and all systems using a PDA. Communication examples: truck data, tachograph, location, charging and discharging data; quality features, SCDS, Transfer methods via: GPS (Global Positioning System), GSM (Global System for Mobile Communications), GPRS (General Packet Radio Service)