Intermec ScanImage 1470 User Manual page 85

FAMILY D
Interleaved 2 of 5 Parameters
Number of Characters
Interleaved 2 of 5 must always encode an even number of
characters. An odd length may be selected to allow an
Interleaved 2 of 5 label to be scanned into an odd-numbered
field. In this case, the reader does not transmit either the first
or last encoded digit. When the last digit is suppressed, the
reader will accept a code which the last character is invalid, e.g.
composed of 5 narrow spaces.
Code Length Selection
In order to minimize the chance of misreads, Interleaved 2 of 5
codes are often restricted to one or a few fixed lengths. The valid
length(s) are selected by the bar code menu, in which case the
user can specify one, two or three lengths, to be accepted by the
reader.
The reader can, if desired, be configured to read and transmit
all lengths of Interleaved 2 of 5. In this case, it is recommended
that a check digit or the Consecutive Same Read Code
Validation features in Family I be activated if a laser or CCD
scanner is used. By activating Consecutive Same Read Code
Validation, the reader is forced to obtain the same read result
on 2 or more successive scans in order to validate the read.
Check Digit
The Interleaved 2 of 5 check digit can be used as the last
encoded character of a label; it is especially recommended when
using Variable Length Interleaved 2 of 5 if the Consecutive
Same Read Code Validation feature discussed above is not
activated.
It is calculated as follows:
1. Add all numbers in the odd place values.
1994 UBI ScanImage User's Manual Page D-3