Single-channel Universal Input schematic with LM76202 field protection, AD7708 ADC measurement core, CD4066 mode switching, HC595 control mapping, and comparator-backed digital input support for DI, analog, 0-10 V, 0-20 mA, resistance, RTD, and thermistor modes.

9V NE555 Latching Trigger to 40 ms Active-Low CD4066B Control Pulse