The video quality is not optimal on some monitors of the system. Do I have to make adjustments to the BUS line?

Yes, you must balance the lines of the system through the selector switch (TV termination) present in intercoms and video intercoms according to their position in the system. The jumper must be set to position A for a non-terminating line, B for a line with a 100 Ohm termination, and C for a line terminated with 50 Ohms (select different endings on each monitor to achieve optimum picture quality).