Rev Counter Board

The rev counter board is located inside the main actuator housing.

Two important functions

As the name suggests, the rev counter board counts revolutions for the main screw. What is not commonly explained is that it also contains the open limit switch.

In order for the system to operate correctly, the actuator must open fully and trigger this limit switch. Then, for the close cycle, the main control board, through the rev counter, counts the number of pulses to the close position.

The number of pulses is what gets saved when the closed calibration is performed.

Practical troubleshooting notes

For many of you, this simple explanation will be all you need to test this component. However, to properly test the rev counter, you will need a high-speed scope.

This board can usually be found pretty inexpensively, so if all other items have been checked and you do not have access to, or knowledge of, the operation of a scope, it is something that can be swapped easily.

Also of note, moisture can cause this board to fail, and sometimes simply drying it out and preventing further water intrusion solves the problem.