CNC Setup Utility Manual
P/N 70000490C - Tuning the Current, Velocity, and Position Controller
All rights reserved. Subject to change without notice.
5-13
10-December-04
Every time the
Start
key is pressed, a plot of the lag, the loaded
MC_2
x
29
,
MC_2
x
30
, and
MC_2231
(only for vertical axes) and the
maximum lag are shown on the MST screen.
NOTE:
If the value of
MC_2
x
30
(coulomb friction feedforward gain) or
the value of
MC_2231
(torque offset, only vertical axes) is zero,
their optimal value is calculated the first time the
Start
key is
pressed. To achieve very small lag values during acceleration /
deceleration (~4 microns) on some systems, it is recommended
that
MC_2
x
23
be adjusted to a little smaller value than the one
calculated in velocity integral tuning.
Miscellaneous Tests
On the MST screen, press
Misc
(
F8
) to display a pop-up menu that
provides the selection of 3 tests:
Current vs. Distance Plot
This test displays a plot of the nominal current against the traveled
distance commanded through Manual Data Input (MDI). The test detects
the differences in friction along the ballscrew length. Thus, this test can
be used to find ballscrew-related problems.
To activate Current vs. Distance Plot test
1. On the Software Options menu, select
Motion Setup/Testing
(MST)
(option 3) and press
ENTER
.
2. On the MST screen, select an axis [
X
,
Y
,
Z
, or
U
]. This activates the
axis.
3. Move the selected axis to one end of its travel.
4. Press
Misc
(
F8
). Select
Current vs. Distance Plot
and press
ENTER
.
5. Press
MDI
(
F5
) and command a move to the opposite end of travel.
This displays a plot of the current, and the maximum, minimum,
average, and standard deviation of the current are displayed in the
MST test window. The plot should be generally flat to indicate no
excessive friction along the ballscrews’ travel.
NOTE:
It is necessary to re-activate the test before each move you want
to plot.
