Galil Motion Control note 3312 Page 3
Acceleration
400,000 cts/s
2
time
0
This is the same effect that an electrical RC filter has on a step shaped voltage versus
time. The filtering of the acceleration versus time will of course change the velocity
versus time into this shape:
Velocity
10
5
cts/s
time
0
The velocity versus time is now S shaped, hence the name S curve profiling. The
amount of smoothing of the acceleration in our motion example is set with the IT
command. The IT command works with acceleration and deceleration of independent
axis motion commands, there is a corresponding command VT for smoothing the vector
acceleration and deceleration in coordinated or linear interpolation motion.
Command Effect
IT
smoothes AC, DC phase of motion due to JG, IP, PR, PA commands.
VT
smoothes VA, VD phase of motion due to VP, CR, LI commands.
