KOPPLINGSANORDNING FOER TELEKOMMUNIKATIONSANLAEGGNINGAR, SPECIELLT FOER TELEFONVAEXELANLAEGGNINGAR, VILKEN HAR ANORDNINGAR FOER SAEKRING AV OEVERFOERINGEN AV KODADE SIGNALER

1. A circuit arrangement for telecommunications exchanges, in particular telephone exchanges, in which binary-coded information is transmitted by means of lines (C, L) which have a line wire for each code element, and in which transmitted information is both stored at the transmitting point (D) and fed to a comparator (V) and also re-stored after its transmission via the line (C, L), and in which the comparator (V) receives the re-stored information and compares it with the stored information, and in which in order to increase the monitoring security the information and a complement, which is formed by the inversion of the information, are used and the comparison of the information and the complement results, and in which a transmitted information item and its complement are received by a receiving device (E) after their transmission via the line (C, L) and are subsequently re-transmitted by said receiving device via the line, characterised in that of the items of information which represent constantly recurrent standard commands, each individual item of information together with its complement is stored in a continuous row of storage units of a command store (A), that when transmitting an information item via the line (C, L), the comparator (V) inverts (in T) the information and the complement thereof upon receipt, in particular after an intermediate storage (in T) and effects a displacement (in W) of the bit forming the information and the complement, whereby both exchange their places within the comparator (V), and that the comparator (V) tests the result of this inversion (in T) and displacement (in W) with the re-stored information (via U) and possibly with the re-stored complement (via U) in respect of coincidence, and that information item and complement are transmitted and re-transmitted constantly and in a fixed time relationship.