| 摘要 |
PURPOSE: A signal generator is disposed in a circuit block which performs delay synthesis of received echo signals to self-diagnose breakage of a delay line disposed in the circuit block making the delay synthesis, and breakage of a signal line from the delay line to the output in a receiving section. CONSTITUTION: A delay circuit 6 to independently give delay to received echo signals is disposed with an adding machine 9, a signal generator 10, and a multiplexer 11 to convey a signal generated in the signal generator 10 to any one of inputs of a delay line 8 in the delay circuit, wherein the signal generator 10 is driven in a self-diagnosis mode of the delay circuit 6, one signal is inputted into any of the delay lines 8 disposed in the delay circuit 6, and breakage of the delay lines 8 and breakage of a signal line from a receiving section to an output are self-diagnosed by detecting conveyance of the signal in a self- diagnostic circuit 4 disposed in a signal processor 2. |
