Omron CS1W-MC221 -, Operation Manual

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Absolute Encoder Interface Specifications Section 9-7
Contents of Absolute Data • Serial Data: Indicates how many revolutions the motor shaft has rotated
from the reference position (specified at setup).
• Initial Incremental Pulse Count: Indicates the number of pulses generated
when the motor rotates to the present position of the motor shaft from the
origin at 83 kHz if the Absolute Encoder is a 30- to 730-W model and
875 kHz if it is a 1- to 5-kW model.
The present position (P
E
) can be determined using the following formula,
where M is serial data (number of motor revolutions), P
O
is the number of ini-
tial incremental pulses counted, and R is the number of output pulses per
motor shaft revolution that is set for the divider circuit.
P
E
= M x R + P
O
P
E
: Present value (servo) read by encoder
M: Number of revolutions (servo)
R: Number of pulses per encoder revolution
P
O
: Number of initial incremental pulses (servo) read by encoder
(normally, negative value)
P
S
: Number of initial incremental pulses read at setup
(normally, a negative value, which will be then stored in the MC Unit)
P
M
: Present value of the system
P
E
= M
×
R + P
O
P
M
= P
E
– P
S
Absolute Data Reception
Procedure Absolute data is processed in the following sequence.
1,2,3... 1. The SEN signal level is set to high.
2. After 100 ms, the system enters serial data reception wait status.
Example
Reference position
(at setup)
Present position (P
E
)
Coordinate value
M value
SEN signal
Phase A
Phase B
Undefined
Serial data Initial incremental
pulses Incremental pulses
120 to 300 ms
Undefined
100 ms max.
10 to 25 ms
1 to 3 ms
25 ms max.
(