ADLINK PCI-8164 - Manual (Page 138)

126 Operation Theory
Constraints of _8164_v_change():
In positioning mode, when changing to a higher velocity, there
must be enough remaining pulses to decelereate after reaching
new velocity, else the _8164_v_change() will return an error
and the velocity remains unchanged.
For example:
A trapezoidal relative motion is applied:
_8164_start_tr_move(0,10000,0,1000,0.1,0.1).
It causes axis 0 to move for 10000 pulses, and the maximum
velocity is 1000 PPS.
At 5000 pulses, _8164_v_change(0,NewVel,Tacc) is applied.
1. To set the maximum velocity, the function
_8164_fix_speed_range() must be used in order
for the function _8164_v_change() to work correctly. If
_8164_fix_speed_range() is not applied, MaxVel
set by _8164_v_move() or
_8164_start_ta_move() automatically becomes the
maximum velocity, where _8164_v_change() can not be
exceeded.
NewVel(PPS) Tacc(Sec)
Necessary remaining pulses
OK / Error
Acceleration Deceleration Total
5000 0.1 300 313 613 OK
5000 1 3000 3125 6125 Error
10000 0.1 550 556 1106 OK
50000 0.1 2550 2551 5101 Error