STSW-SPIN3202 to drive our own motor and can't drive to the target speed

Hello, 

I use STSW-SPIN3202 to drive our own motor, the maximum speed is about 1800RPM(12V, 40A, max speed 2400RPM), but I use other motor driver, it can drive above to 2400RPM. 

When the motor's speed is above 1800RPM drived by the STSW-SPIN3202, it will stop the motor without any error message.

I want to know what can I do.

Thanks