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Position Object Detector

MS-880 Industrial Long Range Scanner User’s Manual A-29

Appendices

Appendix K — Position Object Detector

In a typical operation, a scanner will wait for bar code data only during a triggered

read cycle. A read cycle is initiated by a “trigger” and can be in the form of a serial

command from the host (internal trigger) or a signal from an object detector (exter-

nal trigger).

When an object detector (also called a sensor, package detector, etc.) is used, it is set

up so that its beam will bounce off the approaching object and the resulting pulse will

be sent to the scanner to begin the read cycle. Typically, a detector is positioned so

that it will detect the presence of an object before its label can be scanned.

An object detector is mounted in almost any position relative to the object as long as

(1) the object passes within range of the detector and (2) direct or reflected light from

the detector does not interfere with the scanner’s reception.

As the item continues to move down the line, its label moves into the scanner beam

and is read by the scanner.

The drawing below shows a label in the picket fence direction with the object detector

positioned so as not to cause interference.

Figure A-6 Object Detector

Bar-coded Object Bar-coded Object

Object

Detector

Scanner

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Microscan MS-4X Manual do Utilizador Página 285