Outputing a high and low value based on a negative or positive signal

I am using Simulink for DC motor control. My motor driver requires a direction input (high or low voltage) corresponding to the direction. Is there a way in simulink that I can get a block to output a 0 or 1 signal based upon whether the input signal has a negative or positive value?

Answer 1

[Matt Kindig]

Hi Joseph,

You could use a switch block ( http://www.mathworks.com/help/simulink/slref/switch.html) where the second input is your input signal (with a set threshold of 0) and the first and third inputs are 1 and 0, respectively.

[Matt Kindig]

Or even better, just use a Compare to Constant block ( http://www.mathworks.com/help/simulink/slref/comparetoconstant.html), which will output a 0 or 1 directly.

Answer 2

[Azzi Abdelmalek]

Use a sign block from simulink/Math Operations . Pass your signal through sign block . the output will be 0 if u<0 and 1 if u>0

[Matt Kindig]

Won't the output of the sign block be -1 if u<0?

[Azzi Abdelmalek]

you are right Matt. we can add 1 and a 0.5 gain block

but your suggestion (compare to cst) is better