Monitor system for a digital signal

A monitor system connected to a digital data processing system, which comprises:

• an analog arithmetic operation device for arithmetically processing a plurality of unknown analog electric quantity signals;
• a multiplexer which is supplied with an output signal from said arithmetic operation device, said plural analog electric quantity signals and an error detection signal denoting a known prescribed electric quantity, and generates output signals corresponding to the plural analog electric quantity signals, the output signal from said arithmetic operation device and the error detection signal successively in a certain prescribed order;
• an analog-digital converter for converting output analog signals from the multiplexer into digital signals and for delivering the digital signals to said digital data processing system;
• and
• a monitor connected to receive the output of the A-D converter and including a digital arithmetic operation device for performing an arithmetic processing corresponding to that of the analog arithmetic operation device, a first comparator for comparing the output of the digital arithmetic operation device and an A-D converted output signal of said analog arithmetic operation device, a discrete register for storing a digital signal of a prescribed digital value, and a second comparator for comparing a digital error detection signal obtained through the A-D converter and the output of the discrete register.