Matrix switch and method of controlling cross point switch of a matrix switch

A switching matrix comprising a plurality of controlling crosspoint switches in a first switching matrix said first switching matrix further comprising a plurality of input lines and a plurality of output lines, said crosspoint switches being located at the intersections of the said lines and interconnecting in a first position an input line to an output line and breaking this connection in a second position,

• a second switching matrix having a plurality of input lines, at least one output line and a plurality of crosspoint switches, each input line of said second switching matrix being coupled to the input lines of said first switching matrix by means of an impedance, the output line of said second switching matrix being coupled to a point of substantially constant potential, selected crosspoint switches of said second switching matrix being adjusted to the first position for terminating with said impedance the input lines of said first switching matrix which were determined by the selected crosspoint switches of said second switching matrix.