PURPOSE: To attain an automatic feeding operation by starting to feed to a transmission path based on a result obtained by collating a dial pulse from an independent communication line to an address number stored in an address setting part.

CONSTITUTION: When a cable is disconnected, an overvoltage (detecting part 3 detects it and a feeding part 2 stops the feeding. When the disconnected cable is restored, the dial pulse is inputted to an input end 5 in the independent communication line. This dial pulse is detected in a dial pulse detecting part 6 and collated to the address number stored in the address setting part 7. Consequently, the two signals coincide, a collation coincidence signal is outputted to an earth transmitting part 8 from a dial pulse detecting part 6. According to an earth signal from the earth transmitting part 6, a feeding control part 9 outputs a driving command for starting to feed to the feeding part 2.