FIELD: systems transmitting binary signals in both directions. SUBSTANCE: proposed system includes reception-transmission unit coupled to adapter connected to communication line, supply voltage unit. Reception-transmission unit is composed of element decreasing resistance of circuit and reception element connected to one output of signal adapter. System is supplemented with at least one load resistor placed between supply voltage unit, another output of adapter and communication line. Signal adapter includes fist element decreasing resistance of circuit, element controlling direction of transmission placed in series in communication line with correspondingly first and second leads-out and which output is connected to controlling input of first element decreasing resistance of circuit connected between communication line and supply voltage unit. Leads-out of element controlling direction of transmission are leads of signal adapter. EFFECT: expanded application field, increased transmission range, flexible control over direction of transmission, simplified design of system. 3 cl, 6 dwg
