Rockwell Automation 1771-DA,D17716.5.13 U MNL 1771-DA ASCII I/O MODULE - Manual (Page 94)

ASCII I/O Module Tutorial
Chapter 4
4Ć20
Next, you will demonstrate the transfer of BCD digits to the data table,
and observe how BCD digits are stored with ASCII characters when the
data string contains both.
2. Enter: ABCD/1234567/A12
Use procedures in section title “Reading Data From Your ASCII Device”
(chapter 1), if necessary.
Procedure P1 Set your industrial terminal to alphanumeric mode
Procedure P2 Enter your data
Procedure P3 Set your industrial terminal to PLCĆ2 mode
Procedure P4 Observe how data is stored in the data table
Results The read block transfer file displays the 15 data characters in
positions 003 thru 010 (Table 3.L).
Table 3.L
Storage of BCD and ASCII Characters
POSITION FILE DATA ASCII Equivalent
001
002
003
004
005
006
007
008
009
010
E010
0000
4142
4344
002F
0001
0234
0567
2F41
3100
status word one
status word two
A B
C D
/
1
2 3 4
5 6 7
/ A
1
Notice the following:
The data string is left justified.
BCD digits in the string are right justified. (The module inserted
leading zeros in positions 005 through 008.)
The number of characters transferred is 15.
3. For comparison, enter a string with a different number of BCD
values. Observe how they are stored.
Enter ABC/123456/A123