How to circumvent built-in PID

I am using V5 motor and PROS(without okapi)
I thought if I directly set voltage will make me disable build-in PID, but here is the result:
I use “move_voltage” function to let the voltage set at 12000mV, below is the voltage I get during the motor accelerate process.(by using “get_voltage” functon)

Because in this task, delay time is 2ms, and the voltage increasing speed become lower. So I think the 10ms built-in PID is still working.
So is anyone have the similar problem?