ADLINK HSL-4XMO - Manual (Page 49)

Operation Theory 39
Figure 4-7: Trapezoidal Motion
There are 2 trapezoidal point-to-point functions supported by the
HSL-4XMO. In the HSL_M_start_ta_move() function, the absolute
target position must be given in units of pulses. The physical
length or angle of one movement is dependent on the motor driver
and mechanism (including the motor). Since absolute move mode
needs the information of current actual position, the “External
encoder feedback (EA, EB pins)” should be set in
HSL_M_set_feedback_src() function. The ratio between com-
mand pulses and external feedback pulse input must be appropri-
ately set by the HSL_M_set_move_ratio() function.
In the HSL_M_start_tr_move() function, the relative displacement
must be given in units of pulses. Unsymmetrical trapezoidal veloc-
ity profile (Tacc is not equal Tdec) can be specified with both
HSL_M_start_ta_move() and HSL_M_start_tr_move() functions.
The StrVel and MaxVel parameters are given in units of pulses per
second (PPS). The Tacc and Tdec parameters are in units of sec-
ond to represent accel./decel. time respectively. Users need to
know the physical meaning of “one pulse” to calculate the physical
value of the relative velocity or acceleration parameters. The fol-
lowing formula gives the basic relationship between these param-
eters:
MaxVel = StrVel + accel*Tacc;