PURPOSE: To attains switching for each equipment with a minimum number of wires by sending an ID symbol of the equipment overlapped on video information on one common video line when the connection between a TV camera to make image pickup and a monitor displaying a picture is switched.

CONSTITUTION: An ID comparator stores a specific number provided in advance into a memory and gives a synchronizing signal to a TV(1-1 or the like) when a received ID signal is coincident with its own specific signal and closes a switch (13-1 or the like) in response to an ON-signal. Then the transmission of an effected video signal is given to a bus line. Image pickup information of a TV camera designated is watched by the operation of an operation panel 11 on a monitor TV3. When other camera is selected, a CPU of the switch 2 generates an ID number of a camera making pickup at present and an OFF signal and gives them to a bus line 5. A designated repeater 4 opens the switch (13-1 or the like) to stop the transmission of the video signal and the ID signal and the ON signal are fed to a bus line to activate the corresponding camera.