User's Manual

CHAPTER FOUR – DATA CAPTURE

4. DATA CAPTURE

SYMBOLOGY-ENCODED TAG READING

On the PL3000 there are two reader options

available for machine-readable, optical tag information.

There is one fundamental difference between the

readers, how they transfer information from tags to

inside their decoding system. A linear symbology

reader illuminates the tag with laser beam and, by default, expects that the

symbol’s spaces reflect more light than the bars. This reader is also referred to as

‘bar code reader’ or to as ‘bar code scanner’. The other reader option is based on

digital camera technology, and the system is commonly referred to as ‘imager’. It

takes an electronic picture that should include the symbol which a user is scanning.

In fact, it takes shots repetitively until the pattern recognition processing has found

a shot including some symbology. (Still, the actual symbol decoding can fail.) The

imager uses red LEDs as a flash which it momentarily switches on and off during

the scanning operation. There are also green LEDs shining an ‘aiming pattern’ that

is used for aligning the reading device to the symbol.

The handling and applicability differences between the readers results from

the above-mentioned technology difference between them. For example, the name

‘bar code reader’ implies that the laser beam is convenient for reading linear (one

dimensional) symbologies but not two dimensional ones. In addition, the bar code

reader is an orientation-dependent scanner, because it scans the laser spot in a

straight line. The visible line shall sweep through all of the bars and spaces of the

symbol so that the reader can succeed in reading the symbol. On the contrary, the

imager can omnidirectionally succeed in reading both the one dimensional and two

dimensional symbologies, assuming that a shot includes the whole symbol being

good enough to be encoded.

Although both the scanners can be configured using specific bar codes, it is

strongly recommended that the changes to the scanner settings are made with the

help of a ‘NID Scanner’ control panel applet. However, the ultimate configuring

should be done in the application software, for example through Nordic ID MHL

API.

Linear Symbology Reader

The bar code reader supports the following bar code types:

• EAN-8

• EAN-13

• UPC-A

• UPC-E

• UPC-E1

• Bookland EAN

• Code 128