Execution of contradictory commands in automatic line block system

Th e automatic line block system may be constructed as a chain of autonomous distributed set of functional blocks located along a railway line section, interlocked by the data transmission subsystem and controlled from two ends of the section. Thus, a certain possibility of simultaneously issued contradictory commands creating conflicts during their execution to be settled by a functional block controlled by them particularly while the data transmission subsystem failure occurs have to be considered. Testing of automatic line block system proper functioning in a range of reaction to contradictory commands and examples of typical conflicts and general rules of solving them are discussed in the paper.