Electronic circuit arrangement for the remote transmission via wire of a digital signal emitted by an emitting device of an electrical state signal, associated with a plant in the field, to a processing unit of said digital signal remote from said plant, characterized in that said circuit arrangement includes: at a transmission end of a wired connection between said emitting device and said remote processing unit, an electronic circuit for the generation of a composite signal for transmission via wire, wherein the composite signal comprises a portion of a signal representative of the logical state of the digital signal emitted by the emitting device and a signal portion for determining the electrical continuity of the transmission link, and at a receiving end of the wired connection, a signal recognition electronic circuit that may be associated with said remote processing unit, in that said electronic circuit for the generation of a composite signal includes: - detection circuit means, adapted to be connected to a signal output of the emitting device and arranged to detect the value of said digital signal at predetermined detection time instants according to an assigned detecting frequency, and - formation circuit means of said composite signal, adapted to generate a signal with a repetitive waveform over time, having a signaling frequency, or a duty cycle in a predetermined signaling period, which is a function of the value of the digital signal detected, and in that said signal recognition electronic circuit is arranged to receive said composite signal and to verify the existence of at least one change in the logical state of said composite signal within a time interval corresponding to a signaling period, whereby the existence of at least one change in the logical state of said composite signal within a time interval corresponding to a signaling period is indicative of the integrity of said wired connection. at a transmission end of a wired connection between said emitting device and said remote processing unit, an electronic circuit for the generation of a composite signal for transmission via wire, wherein the composite signal comprises a portion of a signal representative of the logical state of the digital signal emitted by the emitting device and a signal portion for determining the electrical continuity of the transmission link, and at a receiving end of the wired connection, a signal recognition electronic circuit that may be associated with said remote processing unit, in that said electronic circuit for the generation of a composite signal includes: - detection circuit means, adapted to be connected to a signal output of the emitting device and arranged to detect the value of said digital signal at predetermined detection time instants according to an assigned detecting frequency, and - formation circuit means of said composite signal, adapted to generate a signal with a repetitive waveform over time, having a signaling frequency, or a duty cycle in a predetermined signaling period, which is a function of the value of the digital signal detected, - detection circuit means, adapted to be connected to a signal output of the emitting device and arranged to detect the value of said digital signal at predetermined detection time instants according to an assigned detecting frequency, and - formation circuit means of said composite signal, adapted to generate a signal with a repetitive waveform over time, having a signaling frequency, or a duty cycle in a predetermined signaling period, which is a function of the value of the digital signal detected, and in that said signal recognition electronic circuit is arranged to receive said composite signal and to verify the existence of at least one change in the logical state of said composite signal within a time interval corresponding to a signaling period, whereby the existence of at least one change in the logical state of said composite signal within a time interval corresponding to a signaling period is indicative of the integrity of said wired connection.