Cognitive Solutions A776 Manual De Usuario

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Chapter 5: Programming commands  105
A776-PG00001 C 12/09 
A776 (B780) Programming Guide
Select PDF 417 parameters
ASCII 
GS p a b c d e f 
Hexadecimal  1D 70 a b c d e f 
Decimal 
29 112 a b c d e f
Value and Ranges:
Value:    
Ranges: 
Description: 
a, b = 
 
 
The ratio of bar height to symbol length. 
a =  
height 
limit 1 to 10 
 
b =  
width 
limit 1 to 100 
 
c =  
rows 
limit 3 to 90 
Number of rows in the matrix of code words. 
d =  
columns 
limit 7 to 30 
Number of columns in the matrix of code words. 
e =  
x dimension 
limit 1 to 7 
Width of a single module in dots. 
f =  
y dimension 
limit 2 to 25 
Height of the code word in dots. 
Defaults: 
a = 1 
 
b = 2 
 
c = 58 
 
d = 7 
 
e = 3 
 
f = 10
PDF 417 is a multi-row, continuous, variable length symbology which has high data capacity. Each symbol has 
between 3 and 90 rows, with each row containing a start pattern, a left row indicator, 1 to 30 data characters, a right 
row indicator and a stop pattern. The number and length of the rows are selectable, which allows the aspect ratio to be 
adjusted to particular labeling applications. There are no separator bars between rows.
Each character has four bars and four spaces within 17 modules, and is assigned a value between 0 and 928. For this 
symbology, it is common to refer to these character values as “code words.”
There are three mutually exclusive sets of symbol patterns, or clusters, each having 929 distinct patterns. Because 
different clusters are used for adjacent rows, it is possible for the decoder to tell if the scanning path is crossing row 
boundaries without the use of separator bars.
Sample symbol description:
Each PDF 417 symbol consists of 3 to 90 stacked rows surrounded on all four sides by a quiet 
zone. Each row contains:
1  Leading quiet zone
2  Start pattern
3  Left row indicator characters (code words)
4  One to thirty data characters (code words)
5  Right row indicator character (code words)
6  Stop pattern
7  Trailing quiet zone
The number of characters in a row and number of rows can be adjusted to vary the symbol’s overall aspect ratio to best 
fit an available space. 
Continued . . .