DETECTION FOR SIGNAL COLLISION

PURPOSE:To detect signal collision without putting restrictions on the distance between devices on a common bus neither decoding patterns, by converting a data string from a transmitting part to a correlation code and modulating a carrier wave with this correlation code to transmit it. CONSTITUTION:A carrier wave 20 is modulated by the correlation code of a code output 30 and is transmitted as a transmission signal 40 onto the common bus. In a receiving part, the transmitted signal is detected by a detector 4 and is sent to a decoder 5 of the correlation code and a correlation code breach detector 6. The decoder 5 decodes it to obtain the original data string, and the correlation code breach detector 6 detects a breach of code rules by a ratio of sine wave noise to carrier to detect collision.