Solution:

Referring to the question about PCL-839, let me explain it as follow: When performing the 'pmove' command, the stepping motor will accelerate from FL to FH and decelerate from FH to FL before it stop. And the PCL-839 card will calculate the accelerate and decelerate time automatically by referring our input steps. In this case, the user only want to run 125 steps, and also the difference between FL and FH is very huge, the time before stop is not enough to complete the velocity profile. That is why user can only see small output pulse. If user can set the steps parameter as a larger number, and he will be able to see the complete velocity profile. You can also test the 'pmove' command with our example 'demo1.c'. And if we monitor the pulse output pin with oscillate scope, we can fine the output frequency increase and then decrease when performing 'pmove'. But if we perform the 'cmove' command, the output frequency increase and dose not decrease.