The way that works is the following.

Lets say we are checking resisters, and need to know if they are within a certain tolerance....

say within 5 pecent....

Your known resistance is 1000 OHMS, and 5 percent is 50 ohms

The ABS function works as the following:

Lets say TEST is 1500 homes

ABS(test-1000)=500

Thus If (test-1000)<50 then output good resistor! (but its not less than 50)

Lets say TEST=900


ABS(test-900)=100 (if the value is negative, it changes to postive)

Thus If (test-1000)<50 then output good resistor! (but its not less than 50)


Lets say TEST = 970
ABS(test-1000)=30

Thus If (test-1000)<50 then output good resistor! (Wonderful!! good part)

Dwayne