Parker 406LXR Series Product Manual page 34

406LXR Series Product Manual
correction in the variable equation, or if your controller has floating decimal scaling (with high enough
precision) the slope correction can be accounted for in scaling.
NOTE: The zero position (or starting point) of the error plots are at the extreme NEGATIVE end of
travel (refer to Chapter 2, Dimensional Drawing, for Negative end location).
Non-Slope Corrected Error Plot
60
50
40
30
20
10
0
Non-Slope Corrected Error Plot, Total error 48µm
Note: Slope Factor is 200µm/m in this example.
Example:
Below is a sample program showing how to correct for slope error using variables. This example
program will work with the 6K as well as the 6000 Series Parker Controllers.
Step 2 through 3 of this program should be made a subroutine. This subroutine can then be executed
for each distance.
Step 1
VAR1 = 1280; IN
Step 2
DEL SLCORR ;
DEF SLCORR ;
VAR2 = (VAR1/1000)* (0.085);
SLOPE FACTOR (mm/meter)
Step 3
VAR3 = (VAR1-VAR2);
Step 4
D(VAR3); SET DISTANCE AS VAR3
END ; END SUBROUTINE
In the example above, the required move distance is 1280 mm. But the LXR has a slope error of
0.085mm per meter. This is a positive slope error meaning that if uncorrected the LXR will move 0.085
mm too far for every meter it travels. To correct we must command a smaller position.
Step 1: The required move distance is set as variable #1.
Positions (mm)
THIS CASE THE DESIRED DISTANCE IS 1280mm.
DELETE SLCORR PROGRAM
DEFINE SLCORR PROGRAM
VAR2 EQUALS DESIRED DISTANCE (IN METERS) TIMES THE
SUBTRACT SLOPE ERROR FROM DESIRED DISTANCE
Slope Corrected Error Plot
6
4
2
0
-2
-4
Slope Corrected Error Plot, Total error 8.5µm
30
Chapter 4 - Performance
Positions (mm)
Parker Hannifin Corporation
EMN Automation - Parker
Irwin, Pennsylvania