Trinamic MONOPACK 2, Руководство пользователя, Страница: 14 / 34

Monopack 2 Manual V1.04 14
Copyright © 2010, TRINAMIC Motion Control GmbH & Co. KG
The figure above shows differences in chopper cycles with fast and slow decay. Fast decay is better at high
velocities, while slow decay shows better performances at low velocities. With the mixed decay feature activated
the modes will be switched automatically for best motor performances. Mixed decay should be switched off in
standstill to avoid possible chirping noise.
4.3 Driving
4.3.1 About the Parameters
Driving is controlled by the bow, acceleration, velocity and pre-divider parameters. See section 4.2.4 for calculating
the step frequency for a given velocity. When driving linear ramps by using command $25 (s. 4.3.8), the microstep
acceleration rate can be calculated as follows:
f
clk
a f a
2 24
2
2 max
f
clk
is 16MHz
f is the pre-divider setting (s. 4.2.4)
a max is the acceleration setting (to be set up using command $14)
Command $23 (s. 4.3.7) uses S-shaped ramps. With these ramps, the bow parameter is used: a high bow value
increases the positioning speed, while a low bow value smoothens the acceleration ramp. The duration of the
bow phase can be calculated as follows (compare to the acceleration and velocity formula):
) 2 /( 1 max/ 256
15 f
clk bow
f bow a t
Attention: The following limitations apply: Do not set the bow higher than about 20 times the acceleration, and
do not set the acceleration higher than about 20 times the minimum required velocity value.
4.3.2 Velocity and Maximum Acceleration ($14)
Set the acceleration and the maximum velocity.
CMD $14
P0 Parameter storage control (s. 4.1)
P1,P2 Maximum Acceleration (1..8191) #
P3,P4 Maximum Velocity (1..8191) #