PURPOSE: To omit the complicated work dependent upon hands by automatically sending talkie data of another preliminarily designated channel at the time of detecting a break of the sound source in a sound source center.
CONSTITUTION: The external sound source supplied from the outside is distributed to an A/D conversion part 303-1 and an attention sound detecting part 303-6. In the case of a break of the external sound source, reception break information is transferred from a reception break detecting part 303-2 to a talkie data inserting part 303-3, and the inserting part 303-3 reads in talkie data of the channel set to an alternative talkie channel setting part 303-5 from a highway bus 304-1 of a control package 304 and inserts it to the talkie sending channel to send it to the highway bus 304-1. That is, the talkie data inserting part 303-3 is provided with the talkie selecting function which automatically performs switching between the external talkie and the stored talkie based on information from the reception break detecting part.
TAKAMI HISASHI
KUBO KAZUHIDE
MATSUO AKIRA
