Production line control
4 – Combinational Logic Design Examples
Rods of varying length (+/-10%) travel on conveyor belt
- mechanical arm pushes rods within spec (+/-5%) to one side
- second arm pushes rods too long to other side
- rods that are too short stay on belt
- 3 light barriers (light source + photocell) as sensors
- design combinational logic to activate the arms
Understanding the problem
- inputs are three sensors
- outputs are two arm control signals
- assume sensor reads "1" when tripped, "0" otherwise
- call sensors A, B, C