the pins b 1 to b 9 and on which the lightning diodes d 1 d 2 and the filters rl 1 co 1 co 2 are assembled in chip on board form the output and voltage of the diodes d 1 d 2 breakdown can of course be selected from among preselected values if required these diodes d 1 d 2 may be mounted serially likewise the value of the inductive resistor rl 1 and capacitors co 1 co 2 will be determined as a function of the type of interference one wishes to filter as it happens circuits for protection against lightning only require a simple connection at a point p 11 p 39 11 p n7 p 39 n7 on the transfer matrix 6 and this without having to perform an interruption of the line l 1 l 2 l n of the interconnecting circuit passing through this point accordingly when it only comprises circuits for protection against lightning the protective module 11 can be removed without the disconnection thereof disrupting the operating of the rack 1 conversely circuits for protection against electromagnetic interference require the mounting of the inductive resistor rl 1 in series on the line and therefore an interruption of this line between the two points to which this inductive resistor rl 1 is to be connected it is obvious that in this case the protective module 11 cannot be disconnected without disrupting the operating of the rack 1 and must be followed by an operation aimed at re establishing the continuity of the lines l 1 l 2 l.