Yaskawa Sigma II Indexer User Manual
Page 98
Sigma II Indexer User’s Manual
Absolute Encoders
5-43
Contents of Absolute Data
• Serial data: Indicates how many turns the motor shaft has made from the reference
position (position specified at setup).
• Initial incremental pulse: Outputs pulses at the same pulse rate as when the motor
shaft rotates from the home position to the current position at approximately
2500rpm (for 16 bits when the dividing pulse is at the default setting).
The final absolute data P
M
can be found by using the following formula:
Where: P
E
=
The current value read by the encoder.
M =
The multi-turn data (rotation count data).
P
O
=
The number of initial incremental pulses.
P
S
=
The number of initial incremental pulses read at setup.
(This is saved and controlled by the host controller).
P
M
=
The current value required for the user’s system.
R =
The number of pulses per encoder revolution.
(Pulse count after dividing by the value of Pn201)
Absolute Encoder Transmission Sequence
1. Turn power on.
2. After 100ms, set the system to serial data reception-waiting-state. Clear the
incremental pulse up/down counter to zero.
3. Receive eight bytes of serial data.
Coordinate value
Value M
Reference position (setup)
-1
0
+1
+2
+3
+3
Current position
+2
+1
+0
PM
PE
PS
PO
M
u R
P
E
= M
u R + P
O
P
M
= P
E
P
S
Forward rotation mode:
P
E
=
M u R + P
O
P
M
= P
E
R
S
Reverse rotation mode:
(Pn0000.0 = 1)
(
)