Microscan MS-710, User Manual

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Chapter 4 Read Cycle
MS-710 Scanner User’s Manual
4-7
4–Read C
y
cle
External Trigger Level
Important: Level and Edge apply to the active logic state (Active Open or Active
Closed) that exists while the object is in a read cycle, between the rising edge and fall-
ing edge. Rising edge is the trigger signal associated with the appearance of an object.
Falling edge is the trigger signal associated with the subsequent disappearance of the
object.
Usage: This mode is effective in an application where the speeds of the convey-
ing apparatus are variable and the time the scanner spends scanning
each object is not predictable. It also allows the user to determine if a
noread has occurred.
Definition: External Trigger Level allows the read cycle (active state) to begin
when a trigger (change of state) from an external sensing device is
received. The read cycle endures until the object moves out of the sensor
range and the active trigger state changes again.
Serial Cmd: < Kg2 >
Figure 4-1 Trigger Level
Initiate Read Cycle:
Object # 1, moving in front of the detector
beam, causes a change in the trigger state,
initiating the read cycle.
End Read Cycle:
The same object, moving out of the detector
beam, causes another change in the trigger
state, ending the read cycle.
Associated waveforms assume
External Trigger State is set
to Active Closed.