Network that transmits data in equidistant cycles

One participant (1) comprises a communication processor (10) which performs a cyclic data transmission. During a cyclic part (ZYK, x) of a cycle (Z, x), are transmitted in which user data, a DP application must not in the memory (14, 15), wherein in the communication processor (10) a process image is held access. To synchronize the communication processor (10) sends the beginning of a cycle a cycle start interrupt (ZSI, x) and the end of the cyclic part (ZYK, x) a cycle end interrupt (ZEI, x). After gaining access, by the computing unit (5, 7, 8), this switches the Interrups again. between two consecutive Interrups access violations are detected and taken appropriate error handling measures; Based on the amount of time (DELTAT'e2,1 DELTAT's2,1).