Omron CJ1W-MA - REV 10-2008, Operation Manual

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Control Units Section 7-2
7-2 Control Units
7-2-1 Control Units for Position Control
Control Units for
Position Control
The command units are used as the basic control units for the position com-
mand values and speed command values that the PCU uses in position con-
trol axis operations, such as direct operation, origin searches, and jogging.
(The unit for speeds is command units/s.) These units are determined by the
electronic gear ratio in the Servo Parameters. The Servo Parameter settings
such as
Positioning Completion Range and Software Limit and the present
position monitor unit input in the CPU Unit are also based on these command
units.
The Electronic Gear Ratio G1/G2 parameters determine the ratio between the
command unit and travel distance (pulse unit) of the Servomotor.
Set the electronic gear ratio such that 0.01
≤
G1/G2
≤
100 when using R88D-
GN
@
G-series Servo Drives, R88D-WT
@
W-series Servo Drives, or SMART-
STEP Junior Servo Drives and such that 0.001
≤
G1/G2
≤
1000 when using
R88D-WN
@
-ML2 W-series Servo Drives.
In the Servo Drive, the control unit is the pulse unit determined by the Servo-
motor's encoder resolution. (The Servo Drive operates internally with a pulse
multiplier of four. Therefore, the Servomotor's encoder resolution multiplied by
four is the number of pulses in one rotation.) The electronic gear ratio is used
to convert the command value (i.e., command units) handled by the PCU into
the control unit (i.e., pulses) used in the Servo Drive (the G1/G2 unit is
pulses/command unit.) When the Servo Drive’s default setting (G1/G2 = 4/1)
is used, the command unit is the number of pulses equivalent to the Servomo-
tor's encoder resolution.
Servomotor with 2,048
(Pulses/Rotation) Encoder When set to G1/G2 = 8192/1000, the command units for which the Servomo-
tor makes one rotation for a position command value of 1,000 can be
obtained.
Model Parameter No. Parameter name Unit Setting range Parameter size Default setting
R88D-GN @ -
ML2
Pn205 Electronic gear ratio 1
(numerator) --- 0 to 131072 4 1
Pn206 Electronic gear ratio 2
(denominator) --- 1 to 65535 4 1
R88D-WT @ Pn202 Electronic gear ratio G1
(numerator) --- 1 to 65535 2 4
Pn203 Electronic gear ratio G2
(denominator) --- 1 to 65535 2 1
R88D-WN @ -
ML2
Pn20E Electronic gear ratio G1
(numerator) --- 1 to
1073741824 4 4
Pn210 Electronic gear ratio G2
(denominator) --- 1 to
1073741824 4 1
SMART-
STEP Junior Pn20E Electronic gear ratio G1
(numerator) --- 1 to
1073741824 4 1
Pn210 Electronic gear ratio G2
(denominator) --- 1 to
1073741824 4 1