Rockwell Automation 1746-QS,D17466.19 SYNCHRONIZED AXES MODULE - Manual (Page 21)

4–5
Publication 1746-6.19 March 1998
Once you have set scale, offset, and extend/retract limits in open-loop
mode, you can now use the Hydraulic Configurator to tune the axis
using closed-loop move commands and axis plots. We suggest that you:
1. Leave un-entered configurations parameters at default, except for:
– Auto Stop to 000E0 (hard stop, only for LDT faults)
2. If not done already, initialize the axes with the “P” command.
3. Store two 6-word motion commands in the Stored Command Editor:
– Mode word = 00000
(This sets integrator to Always Active and accel/decel to slow ramp.)
–
SPEED, ACCEL , and DECEL values at 20% of typical machine move
(For safety, start slow and increase SPEED gradually.)
– COMMAND VALUE s to desired end positions for the axis to tune
– Zero all six command words of the axes not to be tuned
4. Set the plot clock (in even-numbered seconds, 20 max) to longer
than you expect for the axis to run “tuning” moves.
5. ATTENTION: Highlight the axis you want to move before moving
the axis back and forth using stored commands [1] and [2] .
Unexpected motion could occur if the wrong axis is highlighted.
6. Open the status bits window (Ctrl-B), and check the STATUS word
for errors while the axis is moving.
7. View captured axis plots (click [ ∩ ] in the ToolBar).
Observe the Sum-Error 2 value displayed in the window.
‘There is no substitute for experience when tuning an axis. This
section offers some guidelines, tips, and suggestions for tuning your
system. While helpful for many systems, they may not be the best
for a particular system. We help you with:
•
General Procedure for Tuning an Axis
•
Adjusting Command-word Speed and Acceleration values
•
Adjusting Feedforward Parameters
•
Using Acceleration Feedforwards
•
Adjusting PID Gains
General Procedure for Tuning an Axis
Use this generalized procedure with the Hydraulic Configurator.
•
Move the axis using stored commands [1] and [2] .
•
Observe the axis plot for each move.
•
Adjust one configuration parameter at a time in the order given.
1. Observe plots of axis moves between the two positions that you
set up with stored commands in the previous section, Getting
Ready. Observe following error, overshoots, and oscillations.
For adjusting command values and configuration parameters, refer to
Adjusting Command-word Speed and Acceleration Values, page 4-7.
Getting Ready to
Tune the Axes
Tuning Each Axis