Microscan Quadrus Verifier, User Manual

Page: 187 / 470

Quadrus Verifier User’s Manual
6-9
Read Cycle
External Level
Important: Level and Edge apply to the active logic state (Active Off (I
OFF
) or Active On
(I
ON
)) that exists while the object is in a read cycle, between the rising edge and falling
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 conveying
apparatus are variable and the time the reader spends reading each object
is not predictable. It also allows the user to determine if a No Read 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: < K200,2 >
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 On.