GC-ATC-106 is powered from the RS-232 data Tx or handshake lines. It will try to get its power from RTS or DTR. If there are no RS-232 control signals (DTR or RTS) available, then the GC-ATC-106 will get power from the data input Tx pin. If no handshake lines are available, and the Tx can not drive GC-ATC-106, then an external power supply can be connected to the +5VDC and GND terminals on the RS-485 connector.
External Power Supply = 5VDC/40mA