Symbol LS 6000 Series, Product Reference Manual

Page: 82 / 175

Programming the LS 6000
5-49
UPC/EAN Predecode Block
UPC/EAN bar codes are made up of two blocks representing
“left” and “right” halves. For example, bar code 1234567890
is divided into left block “12345”, and right block “67890”. To
maximize its aggressiveness, the LS 6000 can decode a UPC/
EAN symbol by “splicing” together a left block read by one
scan line, and a right block read by another.
Reject Predecode Block
This option provides additional protection (beyond the
embedded check digit) against mis-splicing a UPC/EAN block
from a symbol that has just been decoded (but has not
completely exited the scanner’s field of view), with a block from
a new symbol that has just been presented to the scanner. This
option requires the scanner to compare the new symbol against
the symbol just decoded to see if there are common blocks. If
either the left or right blocks match between symbols, the
scanner rejects the common block for the programmed Decode
Time-Off interval.
REJECT PREDECODE BLOCK