Siemens SIMOVERT MASTERDRIVES Manual page 785

05.2006
9.7.2.10 Setting the parameters for the virtual master axis
Nesting the virtual
master axis in the
sampling time
U953.34=4 ; Nest virtual master axis in sampling time T4
(=2
Input signal and
enable signal of
virtual master axis
U689=18 ; Enable for virtual master axis [832.2] together with
; start command from terminal 7 [90]
U681=11 ; Velocity setpoint for virtual master axis
; [832.1] from potentiometer at analog input [80]
Rated velocity and
acceleration ramp
for virtual master
axis:
U682=1 000 000 ; Rated velocity for virtual master = MD23
; =10 000 000 LU/min (input in [10 LU/min]), this
; equals
; P353)
U685=167 ; Acceleration for velocity ramp-function generator
; in virtual master axis [832.5] =
; (10 000 000 LU/min) / 1s = 166 667 LU/s2
; (input in [1000 LU/s2]
Setting the axis
cycle length of the
virtual master axis
U687=36 000 ; Axis cycle length for the virtual master [832.6]
; = 36000 LU equal to 10 motor revolutions each
; with 360.0°
Siemens AG 6SE7087-6QX70 (Version AG)
SIMOVERT MASTERDRIVES
The virtual master axis
used independent of positioning and synchronization). It is activated
with the following parameter setting and is nested in the same sampling
time as the positioning system:
4
*T0=16*200µs=3.2 ms for converter frequency 5 kHz)
The virtual master axis is enabled in this application example together
with the start command for positioning (terminal 7; see Fig. 9-46). The
input velocity setpoint is transmitted from the potentiometer at the
analog input (terminal 9/10):
The rated master velocity (maximum machine velocity) in this example
is set to the same value as the maximum traversing velocity MD23 for
positioning:
2778 min-1 on the motor shaft (see
We will assume an acceleration time for the virtual master of 1 s for
acceleration from 0 to the rated velocity of 10 000 000 LU/min
configured in U682. This corresponds to the following acceleration:
The axis cycle length for the virtual master ACL_V in this application
example is the same as the rotary slave axis length of 36000 LU
defined in MD11 for the positioning functions; this equals 10 motor
revolutions with 3600 LU each (1 LU = 0.1°):
(1LU = 0.1°; see AVWF)
Compendium Motion Control
[832] is a separate free block (which can be
Technology Option F01
[832.2]
9-137