The RX250AL Receiver logger is the heart of a GenII logging system. Because the RX250AL is responsible for receiving and storing the data, it is not necessary to have a PC permanently connected. The built-in battery means data logging is not interrupted even if there is a temporary AC mains failure. Multiple RX250ALs can be used for wide area coverage. Alarms (including SMS alarms) come as standard. (To use SMS alarms, a GSM modem is required).