SIXpack 2 – Manual (V1.10 / January 29
th
, 2010)
28
6.3
Adjusting SIXpack 2 to motors micro step characteristics
6.3.1
Calculation of micro step frequency
The SIXpack 2 operates with a fixed micro step frequency of 16 micro steps every full step. The programming
positions are specified in micro steps in relation to zero. Following formula calculates the given motors micro
steps for a whole rotation:
Number of micro steps / rotation = 360° / Full step angle * 16
The full step angle is specified in the motors datasheet.
The absolute micro step frequency, the number of steps per second, in relation of the motors actual velocity
settings is described with following formula:
i
div
i
clk
step
micro
v
clkdiv
f
f
14
2
1
Full step frequency = 1/16micro step frequency
f
clk
is 20MHz
Clkdiv
(ClockDivider
, $12, SQPack-Tab “Velocity & Acceleration”) is the same for all motors (value range
0…31)
v
i
respectively
vakt
is the velocity of each motor (range: –511..+511)
div
i
(
Div
, SQPack-Tab “Velocity & Acceleration”) can be parameterized for each motor (range 0…3)
Note: The micro step frequency must not exceed 200 kHz.
6.3.1.1
Example
The starting position (get with
GetPositionAndActivity
, CMD $20, set with
SetActualPosition
,
CMD $27) is zero,
target position is 116666 (refer to command
StartRamp
, CMD $23).
Actual full step frequency (
f
full-step
) is calculated with given formula for
f
micro-step
by multiplication with 16.
VAkt
for
accelerations is:
ms
2
t /
AMax/64
+
VStart
VAkt
This formula is not valid for decelerations. To realize the actual function the SIXpack 2 decelerates more slowly
than it accelerates.
Parameter:
ClockDivider
= 5,
Div
= 2,
VStart
= 16,
VMax
= 128,
AMax
= 5
