Hi, Dear DJI Lightbridge users, Considering the needs of 1 pilot solution, DJI will release a new firmware for Light Bridge (LB) this week. With this firmware, when Tx A 8CH (via Red plug) and Tx B 8CH (via Black plug) are connected to LB ground system, the Dbus port of LB air system will output total 16CH, while Gimbal port will output 8CH of Tx B for Zenmuse HD gimbal. When only 1 Tx A with less than 16CH is connected via Red plug, all channels will be detected and sent to LB air system, which will output all channels via Dbus port. In this case, Gimbal port will not send any channel signal to Zenmuse HD gimbal. Please click http://www.dji.com/product/dji-lightbridge for more information.