Trinamic TMCM-610, Руководство по оборудованию, Страница: 21 / 24

TMCM-610 Hardware Manual (V1.14/2010-APR-30) 21
Copyright © 2010, TRINAMIC Motion Control GmbH & Co. KG
8 TMCM-610 operational description
8.1 Calculation: velocity and acceleration vs. microstep- and
fullstep-frequency
The values of the parameters, sent to the TMC428 do not have typical motor values, like rotations per second as
velocity. But these values can be calculated from the TMC428 parameters, as shown in this document.
Parameters for the TMC428:
Signal Description Range
f
CLK
clock-frequency 0… 16 MHz
velocity - 0… 2047
a_max maximum acceleration 0… 2047
pulse_div
divider for the velocity. The higher the value is, the
less is the maximum velocity
default value = 0
0… 13
ramp_div
divider for the acceleration. The higher the value is,
the less is the maximum acceleration
default value = 0
0… 13
Usrs microstep-resolution (microsteps per fullstep = 2
usrs
)
0… 7
(a value of 7 is internally
mapped to 6 by the TMC428)
Table 8.1: TMC428 velocity parameters
The
microstep-frequency of the stepper motor is calculated with
32 2048 2
velocity ] Hz [ f
] Hz [ usf
div _ pulse
CLK
 


with usf: microstep-frequency
To calculate the
fullstep frequency from the microstep frequency, the microstep frequency must be divided by the
number of microsteps per fullstep.
usrs
2
] Hz [ usf
] Hz [ fsf

with fsf: fullstep-frequency
The change in the pulse rate per time unit (pulse frequency change per second – the
acceleration a ) is given by
29 div _ ramp div _ pulse
max
2
CLK
2
a f
a
 


This results in acceleration in fullsteps of:
usrs
2
a
af

with af: acceleration in fullsteps