Method for checking protective instruction transmission systems in on- line operation

摘要

A method is provided for checking the operability of protective instruction transmission systems in on-line operation in which at least two stations, particularly multi-instruction equipment, are connected to one another by transmission links and communication channels. The stations each comprise instruction input and output lines for checking the protective instructions and a first station controlling and checking of the operability transmits a test signal to a second station to be tested, the second station returning the signal to the first station unaltered. Upon receipt of the test signal, the respective inhibit of the instruction input and output lines is effected in the first and second stations. Simultaneously, the first station emits the first test instruction which the second station returns to the first station immediately after receipt and, therefore, effects the transmission of further test instructions in the first station. A test function sequence formed of a plurality of test instructions is terminated by transmission of an idle instruction which cancels the inhibit of the instruction input and output lines in the first station and in the second station.