The GP-30 is a RFID (Radio Frequency
Identification) Proximity reader designed to fit inside a standard
electrical gang box. Card data is transmitted via a RS-232 serial
connection at 9600 baud. The GP-30 takes regulated DC power between
5 and 13.5 V. Proximity sensing range depends on the power; at 5
V the range is 20 cm. The GP-30 interfaces with RFID cards at the
standard 125 kHz frequency.