ADLINK PCI-8164 - Manual (Page 97)

Operation Theory 85
4.1.8 Relationship between velocity and acceleration
time
The maximum velocity parameter of a motion function will eventu-
ally have a minimum acceleration value. This means that there is a
range for acceleration time over one velocity value. Under this
relationship, to obtain a small acceleration time, a higher maxi-
mum velocity value to match the smaller acceleration time is
required. Function _8164_fix_speed_range() will provide
such operation. This function will raise the maximum velocity
value, which in turn results in a smaller acceleration time. Note it
does not affect the actual end velocity. For example, to have a
1ms acceleration time from a velocity of 0 to 5000 (pps), the func-
tion can be inserted before the motion function as shown.
_8164_fix_speed_range(AxisNo,OverVelocity);
_8164_start_tr_move(AxisNo,5000,0,5000,0.001,0.001);
How do users decide an optimum value for “OverVelocity” in the
_8164_fix_speed_range() function? The _8164_verify_speed()
function is provided to calculate such value. The inputs to this
function are the start velocity, maximum velocity and over velocity
values. The output value will be the minimum and maximum val-
ues of the acceleration time.
For example, if the original acceleration range for the command is: