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Unattended Barcode Scanning Application - things to consider

By aisltd, Wednesday, 7th June 2017 | 0 comments
Filed under: Publications.

Through the years, we have found that a little up-front planning and a few simple questions can ensure a successful fixed barcode scanner application.

There are many different types of fixed mount scanners – one of the most noticeable differences is in the scan patterns emitted.

Although the most common type of scan pattern is a straight line, other patterns include: fixed raster line, moving raster, and omnidirectional scanners

The following questions should help you to plan your own installation, by considering such criteria as:

  • How fast is the label moving past the scanner? 
  • How far away is the label and how much will that distance vary?
  • Can the scanner read your label at the desired distance?
  • How does the scanner know when to read and output the label data?

Probably the most complicated part of a moving-beam scanner application is determining whether the scanner is fast enough to scan a particular label reliably.

Although a scanner can successfully read a barcode in two scans, experts generally recommend a minimum of five scans to read a well-printed label reliably.

The following formulas are useful for calculating how many actual guaranteed scans will occur given any combination of label size, speed, and orientation.

The number of effective scans from a passing label is determined by:

  • Scan rate  
  • Direction of label travel
  • Speed at which the label passes
  • Barcode label dimensions

In planning your installation you should also consider the following –

  • Can you place the label in the ladder orientation? This orientation affords more chances to read a damaged label, and label placement is not as critical as in a picket fence orientation. In general, resort to a picket fence setup only if the ladder mode won’t work in your application.
  • Have you avoided tilt, pitch, and skew of the label as much as possible?
  • Have you avoided the scanner’s specular reflection zone? The specular reflection zone is a narrow zone in which direct, non-diffused light returns to the scanner blinding the scanner and makes reading a label impossible.
  • Optical throw and depth of field?
  • System Considerations?
  • Scanner Mounting and Environment?

Here at AIS Ltd, we are experts in the implementation of fixed position scanning systems including industrial scanner networks, conveyor based product scanning and embedded scanner integration. Feel free to contact us to discuss your application with one of our Engineers.