Abstract: A device for fixing a housing of an electronics module includes an intermediate part (6) on which the housing (1) is fixed, and also includes a rail (5a) for receiving the housing (1) and the intermediate part (6), said intermediate part (6) including a locking element (21) that carries a catch (30) suitable for co-operating with complementary relief on the intermediate part (6) to hold the locking element in a retracted position, from which it is released when the intermediate part (6) and the housing (1) are put into place on the rail (5a).

Abstract: A system comprises a central unit and a plurality of display modules each adapted to show on a display information received from the central unit, for example for displaying prices in a store. The central unit comprises a transmitter including a current loop fed with a low-frequency signal modulated according to the information to be transmitted and the system comprises, associated with each display module or group of display modules, a receive circuit, a receive antenna coupled electromagnetically to said current loop and a device for activating the receive circuit at predetermined periods for a limited duration. Each transmission of information by the central unit is preceded by the transmission of a reactivation signal which, when detected by the receive circuit during a phase in which the latter is active, causes it to be held in the active state for at least part of the duration for which said information is transmitted.