DIGITAL TRANSMITTER

PROBLEM TO BE SOLVED: To provide a standby mode as a power source mode, while using a time division multiplex system by operating a circuit in a standby power source mode at the time of standby and switching to a power source for an operation at the time of system information generation. SOLUTION: At the time of the standby, the power of a standby power source 105 for terminal station supply is passed through a switching device 103, the power source mode is judged in a power source judgment circuit 106 on a terminal station side and it is connected to the power source 108 for the standby. In this case, input is converted to the standby power source for a terminal and a digital information GEN circuit 109, a transmission circuit 110 and a digital transmission processing circuit 111 are driven. In this case, when an operation state is attained, the GEN circuit 109 prepares system information by digital signals and outputs it through the transmission circuit 110 and the transmission processing circuits 111 and 112 to a reception circuit 113. In this case, high level signals are inputted to a standby/operation CTL GEN 114, a switch 116 is controlled, an operation power source 117 for the terminal station supply is driver, and the power source for the operation is supplied to the terminal side.