All AlarmDecoder products require all 4 wires including Red and Black for power in order to power the signals to the panel. The AD2PI board is powered by the Pi power supply but still needs the alarm panel power for signaling.

Power requirements vary depending on your device type.

Product Name	Power Usage	Input Voltage	Voltage Source
AD2USB	~30mA	12V	Panel
AD2SSERIAL	~30mA	12V	Panel
AD2PI	~30mA	3.3V or 5V	Raspberry Pi