PURPOSE: To improve the manipulation and maintenance of a radar by inputting a radar control signal to a computer by use of a pin board of simple structure and then by judging the selected and unselected state of an antenna module accurately and rapidly.

CONSTITUTION: To computer 2, pin board 10 is connected as well as control panel 1. This board has pin board 11 provided with many holes 12, which correspond to antenna modules 7. To select a desired antenna module, a pin is inserted into the corresponding hole 12 and an antenna module control signal is generated. The combinational state of modules 7 is read by computer 2 and information on the result of calculation processing is stored in registers 4 through logic circuit 3 and sent to modules 7. Consequently, modules 7 are brought under on-off control to set the same state that pin board 10 is set and then the radar is put into operation, so that the manipulation and maintenance of the radar can be improved.