Omron SYSMAC CS1G Operation Manual page 561

Program Example
Explanation of the
program
10-1-11 Positioning with Circular Interpolation of Higher Path Accuracy
Explanation of the
operation
538
Main program
01) A program No. and axes to be used are specified.
02) With WHILE command, the process through 02) to 23) is repeated until
the general input (IW0B00) becomes 1.
03) With WAIT command, the program advance will be held until the general
input (IW0B01) becomes 1.
04) The present position is written to the position data (PL0020).
05) The travel distance is calculated with the target position (PL0000) and the
present position (PL0020), and the result will be entered into the position
data (PL0022).
06) The subprogram (P502) is called and executed.
07) to 17) The rotation direction and the travel distance are calculated and
entered into the position data (PL0002).
18) Positioning is performed based on the calculated position data.
19) The program advance will be held until positioning is completed.
20) 1 is output to the general output (OW0BA0).
21) The program advance will be held until the general input (IW0B01)
becomes 0.
22) 0 is output to the general output (OW0BA0).
23) This is the end of WHILE command from 02).
24) The program is completed.
Subprogram
01) A program No. and axes to be used are specified.
02) to 04) When data exceeding 360 degrees is entered into the position data
by mistake, the target position is corrected to the value within the
range 0 to 360 degrees and the main program is resumed. (When
an appropriate target position is entered in the position data, the
subprogram does not do anything and the main program is
resumed.)
05) The program is completed and the main program is resumed.
• The operation is the same as "_Positioning with Linear and Circular Inter-
polation", however, the path accuracy is raised.
• When performing circular interpolation, the faster the feed rate is, the
more inside of the expected circular arc the axes tend to travel. To deal
with this tendency, setting higher feed forward gain can raise the path
accuracy. Generally speaking, setting the feed forward gain of the servo
system too high causes overrun (Overshoot) when stopping or reversing
at the target position. To prevent this, the feed forward gain of 20% for lin-
ear interpolation and 60% for circular interpolation are set in this example.
Section 10-1