Omron trajexia CJ1W-MCH72 Operation Manual page 291

How-to's
5-1-2-2 Position mode examples
280
CJ1W-MCH72
SERVO = OFF
Profile generator
Position Loop is
deactivated
(Gains are not
used!)
Demanded
position
Measured
position
In this mode the position and speed loop are closed in the Servo Driver. The
CJ1W-MCH72 sends the position command through the MECHATROLINK-II
network to the Servo Driver, and reads the position feedback.
Note that this system has no sample delay as compared to the position loop in
the Servo Driver, the Demanded Position in cycle "n" with the Measured
Position in cycle "n".
The CJ1W-MCH72, for the internal handling, continues to use its own position
loop, so the Following Error that read in the Axis parameter in the CJ1W-
MCH72 is not the real one in the Servo Driver. To read the correct Following
Error use DRIVE_MONITOR.
Adjust the rigidity of the servo, the speed loop gain and the position loop gain
at the same time using just proportional position gain. The results are similar
to the MECHATROLINK-II Speed mode with the advantages:
• The tuning is more simple, only the rigidity (Fn001) and, if necessary, the
feedforward gain (Pn109) needs to be set.
• The position loop in the servo is faster (250µs) than in the CJ1W-MCH72
and it is turned together with the speed loop.
• There is no sample time delay between "Target position" and "Measured
position".
To do a finetune the different gain parameters can be changed individually.
BASE(0)
ATYPE=41 'MECHATROLINK Position mode
SERVO=1
DRIVE_CONTROL=2 'To monitor the Following Error in
'DRIVE_MONITOR
WDOG=1
DEFPOS(0)
loop:
MOVE(81920)
WAIT IDLE
WA(100)
DEFPOS(0)
GOTO loop
SERVO = OFF
Position loop
+
_
Following Speed
error command
Section 5-1
SERVO
ML-II
Position
Position Loop
command
Speed Loop
Torque Loop
E M