NCR RealPOS, User Manual

Page: 42 / 187

4-6 Chapter 4: Operating the Scanner
Distance from Scanner
For optimum reading, the distance you must place the label from the 7893 depends on the
density and height of the bar code. You can relate this to focusing a camera, where you change
the focus setting based on how far away the object is.
Depending on the label, reading can range from zero to six inches. Therefore, when you use
your scanner, move the label toward the scanner to a comfortable distance in front of the scan
window (approximately three to four inches) and hold the item momentarily. Normally the
"Good Read" indication occurs within one fourth of a second. If this does not happen, try
moving the label a little closer to the scanner.
Bar Code Quality
The ability of your 7893 to read bar code labels depends greatly on the quality of the label.
Although the 7893 can often read bar codes that appear to be bad, it cannot read bar codes that
are obstructed, defective, or damaged. If the scanner cannot read the bar code, you must key in
the merchandise information at the host terminal and go on to the next item. Be sure to tell
your supervisor if many bar code labels are defective. The figure below shows some examples
of bad bar codes. These are only examples and are not all-inclusive.
0 1 2 3 4 67 8 5 9
0 6
0 1 2 3 4 67 8 5 9
0 6
0 1 2 3 4 67 8 5 9
0 6
R0026
0 1 2 3 4 67 8 5 9
0 6
0 1 2 3 4 67 8 5 9
0 6
0 1 2 3 4 67 8 5 9
0 6
Bar Code Scratched Bar Code Folded Bar Code Truncated
Bar Code Torn Poor Color Contrast Red Bar Code On
Red Background
The readability of a label depends on variables such as sizing, placement, color, paper type, ink
viscosity, and package coatings. The middle of a printing run can yield erroneous labels due to
the many variants involved. In particular, poor color contrast and marginal print quality can
make a label hard to read.
A label should be considered readable if it meets or exceeds the requirements set forth in the
EAN UCC
General Specification 1/2000.