Abstract: The invention relates to a system for data transmission in analog form in which data is coded such that a pulsed bivalent signal is obtained which can be physically integrated; this bivalent signal, considered as formed by a juxtaposition of elementary bits at a higher rate is processed in a DELTA demodulator as if these elementary bits were the digital representation of an analog signal which has undergone a corresponding DELTA modulation. Data is transmitted in the form of the analog signal delivered by this demodulator. On reception, the analog signal received is applied to a DELTA modulator which operates preferably in slope overload and which supplies a DELTA bit train reproducing the bivalent transmission signal of the transmission and enabling the signals to be restored after decoding.