EA/EB: EA/EB is the enable pin for the two motor A/B, the motor speed also can be controlled by the PWM of this pin.
Putting on the jumper enable the pull up resistor for the microcontroller, putting off it disable it. The power of logic circuit of the board is supplied by the 5V port when this jumper put off. When the jumper is put on, The 78M05 supplies the 5V power for logic circuit on the board from the VMS port(7V < VMS < 18V). 5V: Power input for the logic circuit on the board.VMS: VMS is the 5V-35V power source for motor.CSB: The current test pin for motor B, this pin can be wired a resistor for current testing or tied a jumper to disable it.CSA: The current test pin for motor A, this pin can be wired a resistor for current testing or tied a jumper to disable it.