I need help to create an electric eye sensor, for a scissor lift table. what i need it to do is. sense when the table is not high enough and activate the motor to turn on and raise the table. I do not know where to find such a sensor, nor do i know what type of sensor i will need. because the table can roll around slightly, it has to be able to read the entire length of the table, not just a small position target. So i will a sensor that can project a laser and read if the reflection is present or not. If not present the table will rise.