Omron SYSMAC CJ Series, Operation Manual

Page: 300 / 371

How-to’s Section 5-1
288
To guarantee the correct overflow both in the CJ1W-MCH72 and in the Servo
Driver, we must set two additional axis parameters:
REP_DIST = 60, and
REP_OPTION = 1. With these settings, the command MOVE(35) rotates the
table 35 degrees in positive direction. The range of possible MPOS and DPOS
values is from 0 degrees to 60 degrees.
!Caution
You must initialize the absolute encoder before you use it for the first time, when the
battery is lost during power off and when the multiturn limit setting in the parameter
Pn205 is changed. The initialization can be done on the display of the Servo Driver or
with the software tool. For more detail on initialising absolute encoder, please see the
Sigma-II Servo Driver manual.
!Caution
It is possible to reset the multiturn counter, but it is not possible to reset the position
within one turn (the fraction from 0 to and excluding 1). To adjust zero offset, use the
parameter Pn808. For more details see the NS115 MECHATROLINK-II Interface Unit
manual.
!Caution
At power up, the absolute encoder position is read from the motor and written to MPOS
using the following conversion:
• For MPOS :
• This is correct if
• If this value is greater than 2
24
, MPOS can have incorrect values at start-up. To
avoid this problem, add the program code DEFPOS = ENCODER/UNITS after all
UNITS initializations.
!Caution
To make sure that the absolute position is always correct, you must make sure that
and that
Note that this is not obvious for the high-resolution encoders of the Sigma-V and G-
Series motors.
Absolute_MPOS = abs_position_encoder
UNITS
1
Pn202
Pn203
.
.
(Pn205 + 1)
Pn202
Pn203
. .
encoder_counts < 2
24
(Pn205 + 1)
..
encoder_resolution < 2
32
(Pn205 + 1)
.
Pn202
Pn203
.
encoder_resolution < 2
32