hi
iam measuring the vacuum using vacuum sensor and displaying on the controller(AD571 ADC,89C51 controller,LCD).
For 0v=10mbar, 1v=20mbar, 2v=30mbar, . . . 9v=90mbar, 10v=100mbar
When I removed sensor from controller it is showing 10mbar (0v) on the display.
How to do when I removed sensor from controller it should display "SENSOR OPEN".
How to detect or sense weather sensor is connected to the controller or not .
Regards nari