6.8 Absolute Encoders
6.8.1 Connecting an Absolute Encoder
6-19
6.8.1
Connecting an Absolute Encoder
If you use an absolute encoder, the encoder divided pulse output signals (PAO, PBO, and PCO) are
output only once when the power supply turns ON. Normally, do not use these signals. Therefore, it is
not necessary to wire the PAO, PBO, and PCO (Encoder Divided Pulse Output) signals. If they need to
be wired, refer to the following section.
4.4.3
Wiring the SERVOPACK to the Encoder
on page 4-26
4.5.3
I/O Signal Wiring Examples
on page 4-34
6.8.2
Multiturn Limit Setting
The multiturn limit is used in position control for a turntable or other rotating body.
For example, consider a machine that moves the turntable shown in the following diagram in
only one direction.
Because the turntable moves in only one direction, the upper limit to the number of rotations
that can be counted by an absolute encoder will eventually be exceeded.
The multiturn limit is used in cases like this to prevent fractions from being produced by the
integral ratio of the number of Servomotor rotations and the number of turntable rotations.
For a machine with a ratio of n:m between the number of Servomotor rotations and the number
of turntable rotations, as shown above, the value of m minus 1 will be the setting for the multi-
turn limit setting (Pn205).
Multiturn limit (Pn205) = m – 1
If m = 100 and n = 3 (i.e., the turntable rotates three times for each 100 Servomotor rotations),
the relationship between the number of Servomotor rotations and the number of turntable rota-
tions would be as shown below.
Set Pn205 to 99.
Pn205 = 100 – 1 = 99
Note: This parameter is enabled when you use an absolute encoder.
Pn205
Multiturn Limit
Setting Range Setting Unit Default Setting When Enabled Classification
0 to 65,535 1 Rev 65,535 After restart Setup
Turntable
Gear
Servomotor
n:m
0
1
2
3
4
5
6
7
8
9
100 200 300 0
100
50
Number of table rotations
Multiturn data
Number of table rotations
Multiturn data
Setting of Pn205 = 99
Number of Servomotor rotations
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