Omron ZW-C1*AT User Manual page 192

● Measurement synchronization
Command
SYNC input
Area
Displacement
sensor 1
Exposure
timing
Displacement
Sensor 2
SYNCFLG output
Response
Area
READY output
(1) The Controller changes the state of the SYNC input signal from OFF to ON.
(2) When receives the SYNC input signal, the displacement sensor turns off the READY output signal, and
starts the measurement synchronization processing.
(3) All displacement sensors that have received the SYNC input signal are synchronized with the end of
exposure and measurement is resumed.
(4) After the end of synchronization, the displacement sensor changes the state of the SYNCFLG output signal
from OFF to ON.
(5) The Controller makes sure that the SYNCFLG output signal has turned ON, and then changes the state of
the SYNC input signal from ON to OFF.
(6) The displacement sensor makes sure that the SYNC input signal has turned OFF, and the SYNCFLG and
READY output signals automatically turn OFF and ON, respectively.
Important
• Be particularly careful of the following points when synchronizing measurement.
- When the exposure time control mode is automatic: Set the exposure time upper limit the same for all
displacement sensors for which measurement is to be synchronized.
- When the exposure time control mode is fixed: Set the exposure time the same for all displacement sensors for
which measurement is to be synchronized.
• By way of reference, the time from acceptance of the SYNC input up to when SYNCFLG output turns ON becomes
"currently set exposure time upper limit + 720 s".
• After multiple displacement sensors are synchronized, they gradually go out of sync. At most 1 s of difference
generates EtherCAT communication between the slave. Input SYNC input signals periodically. The maximum
deviation time can be calculated with the following formula.
Difference in EtherCAT + Exposure time (maximum) × 2 × Average number of repetitions × 24 ppm
Example: Exposure time (maximum): 1 ms, average number of repetitions: 64
1 s + 1 ms × 2 × 64 × 24/1000000 = 4.072 s
The maximum deviation time will be 4.072 s.
• The displacement sensor starts resetting the filtering process after receiving a SYNC signal. If the average number
is set to 128 times, please note that the measurement value will not be finalized until the measurement is done 128
times. You can check whether the measurement value is finalized if either of HIGH, PASS or LOW signal turns on in
the response area.
190
EtherCAT Connection
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
(1) (2) (3) (4) (5) (6)
ZW User's Manual