An optoelectronic system, realizing the halfadder system, which can be used in the transmission and processing of signals in optical form, is described. The halfadder system has been realized based on photoconducting (PC) and electroluminescent (EL) thin film elements. The halfadder system should realize two logical functions: EX-OR and AND. In the presented paper the system realizing the EX-OR logical function, constructed by a suitable connection of eight photoconducting and five electroluminescent elements, and the system realizing the AND function composed of two photoconducting and one electroluminescent elements, are described. The dependences on time of the output signals were measured for various combinations of the input signals: L1=L2=0; L1=20 lx, L2=0; L1=0, L2=20 lx oraz L1=L2=20 lx. For the halfadder system the signal at the AND function output appeared only when both the input signals had the value corresponding to logical one, and at the EX-OR function output, when the input signals had various values (the first signal was zero, and the second was one or inversely). Thus the investigated system fulfilled the role of a halfadder realizing the function EX-OR, and the function AND, respectively.