Rate controllers are commonly used on fertilizer application systems for seed drills and planters; accurately and reliably controlling rate of flow by regulating the speed of a 12 volt pump.
If you are having issues with your controller, here are some helpful resources to diagnose problems with you PWM board.
40 Amp PWM Electric Motor Driver
Our JDS 25 and JDS 10 controllers use the same signals as shown on the document above.
For more manuals and literature. https://micro-trak.com/product/electric-motor-driver/