JPS57207462A - Monitor device - Google Patents

Abstract

PURPOSE:To provide general-purpose performance for the constitution of a device and to attain high speed without using ROMs and the like, through the confirmation if a normal reception state is given or not, by detecting the difference between a reception signal and a discriminated value and comparing an output smoothing the detected value and a prescribed value. CONSTITUTION:An input 100 is inputted to a synchronizing detection circuit 1, two orthogonal base band signals are outputted from the circuit 1 and applied to error detectors 6 and 6'. An error between a reception and a discriminating value is detected at the discriminators 60 and 60' of the detectors 6 and 6', subtractors 61 and 61' compare the reception signal and the discriminating value and the difference is detected. The output of subtractors 61 and 61' is rectified at full-wave rectifying circuits 62 and 62', and the output of the circuits 62 and 62' is synthesized at an adder 7. A signal corresponding to the difference between the reception signal and the discrimination value from the adder 7 is smoothed at an LPF4 and compared with a prescribed reference at a comparator 5 without the use of ROMs by confirming whether or not the normal reception state is obtained.