Using the channel tester, the different signal lines of an I/O channel can be tested.
The red and green LEDs show the status of the digital output line.
Red: low (0v)
Green: high (5v)
The slide switch and push button will set the digital input state.
Slide switch position
Left: low (0v)
Right: high (5v)
Push Button position
Down: low (0v)
Up: high (5v)
Note: For the push button to function properly, the slide switch need to be set to the left (high).
A thumb-wheel potentiometer is used to set a voltage on the analog input line.
The circuit diagram for the tester is as follows: