Di-soric ID-01, Руководство пользователя

Страница: 65 / 222

Number of Symbols
4- 7
ID-01 Laser Scanner User’s Manual
External Level
Important: Level and Edge apply to the active logic state ( Positive or Negative )
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 convey-
ing apparatus are variable and the time the reader spends scanning each
object is not predictable. It also allows the user to determine if a noread
has occurred.
Definition:
External Level allows the read cycle 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
>
1
Object
detector
Object
detector
1
0
Positive
0
Positive
External Level Trigger
Initiate Read Cycle:
Object # 1, moving in front of
the detector beam, causes a
change in the trigger state, initi-
ating 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 Positive.
MS-3 Laser E.book Page 8 Monday, August 30, 2004 11:09 AM