This trigger cable transmits 8-bit trigger markers. The output of the trigger cable is usually TTL (transistor-transistor logic), meaning 5 V for High and 0 V for Low. However, other voltage levels or an AC signal can be transferred with this trigger cable. One end of the trigger cable is a D-Sub 25 pin connector, connected through to multiple BNC output cables (4 remain unused and are not internally connected), only the first eight are used. Pins 2-9 of the D-Sub 25 connector map to BNC output cables 1-8. Pin 25 is used as ground (GND) and are part of the BNC plug. The cable's length is 20cm and is connected to an adapter cable.