The PCR-942 is a proximity card reader
and keypad that sends and receives data via a RS-232 interface. 9600
or 19200 baud transmission speed. Using switch-settable addresses,
up to 16 units can use the same RS-232 bus. 10 cm (4 in) RFID read
distance. The PCR-942 interfaces with RFID cards on the standard 125
kHz frequency.