System for the detection and the location of an attempt at intrusion into a perimeter defined by a fence, said fence comprising retention elements and elements for anchoring to the ground such as posts, said system for detection and the location comprising (i) at least one management unit, (ii) a plurality of means for detection of impacts and/or vibrations capable of occurring on said fence, connected to each other via a cable called detection cable, said detection cable being connected to said at least one management unit, (iii) a data-processing station connected to at least one of said management units, (iv) means for transmitting data from at least one of said management units to the data-processing station, (v) optionally one or more end units for ending a free end of said detection cable, said system being characterised in that - each detection means (Dn) is directly connected, optionally via a connection unit, on one side to another detection means (Dn+1 or Dn-1) and on the other side: -- either to another detection means (Dn+1 or Dn-1), -- or to a management unit, -- or to an end unit; and - each detection means (Dn) sends data in the form of frames of digital signals to the detection means (Dn+1 and/or Dn-1) and/or to the management unit to which it is directly connected; and - each detection means (Dn) receives data in digital form from the detection means (Dn+1 and/or Dn-1) and/or from the management unit to which it is directly connected; and - a detection means (Dn) that receives data on one side transmits it to the detection means (Dn+1 or Dn-1) or to the management unit to which it is directly connected on the other side; and - each detection means (Dn) transmits, to the detection means (Dn+1 and/or Dn-1) and/or to the management unit to which it is directly connected, data in digital form on events that it has detected, - the management unit sends, at regular intervals, a request signal in the form of a frame of bytes called "request frame" to the detection means to which it is directly connected, - said detection means adds, after reception of said frame, its individual identifier, preferably in the form of a serial number, and transmits it to the detection means and to the management unit to which it is directly connected. (i) at least one management unit, (ii) a plurality of means for detection of impacts and/or vibrations capable of occurring on said fence, connected to each other via a cable called detection cable, said detection cable being connected to said at least one management unit, (iii) a data-processing station connected to at least one of said management units, (iv) means for transmitting data from at least one of said management units to the data-processing station, (v) optionally one or more end units for ending a free end of said detection cable, - each detection means (Dn) is directly connected, optionally via a connection unit, on one side to another detection means (Dn+1 or Dn-1) and on the other side: -- either to another detection means (Dn+1 or Dn-1), -- or to a management unit, -- or to an end unit; and -- either to another detection means (Dn+1 or Dn-1), -- or to a management unit, -- or to an end unit; and - each detection means (Dn) sends data in the form of frames of digital signals to the detection means (Dn+1 and/or Dn-1) and/or to the management unit to which it is directly connected; and - each detection means (Dn) receives data in digital form from the detection means (Dn+1 and/or Dn-1) and/or from the management unit to which it is directly connected; and - a detection means (Dn) that receives data on one side transmits it to the detection means (Dn+1 or Dn-1) or to the management unit to which it is directly connected on the other side; and - each detection means (Dn) transmits, to the detection means (Dn+1 and/or Dn-1) and/or to the management unit to which it is directly connected, data in digital form on events that it has detected, - the management unit sends, at regular intervals, a request signal in the form of a frame of bytes called "request frame" to the detection means to which it is directly connected, - said detection means adds, after reception of said frame, its individual identifier, preferably in the form of a serial number, and transmits it to the detection means and to the management unit to which it is directly connected.