Rockwell Automation 1771-DA,D17716.5.13 U MNL 1771-DA ASCII I/O MODULE - Manual (Page 95)

ASCII I/O Module Tutorial
Chapter 4
4Ć21
Results The read block transfer file displays the 15 data characters in
positions 003 thru 010 (Table 3.M).
Table 3.M
Storage of BCD and ASCII Characters
POSITION FILE DATA ASCII Equivalent
001
002
003
004
005
006
007
008
009
010
E010
0000
4142
432F
0123
0456
2F41
3132
3300
0000
status word one
status word two
A B
C /
1 2 3
4 5 6
/ A
1 2
3
Notice the following:
The module used fewer leading zeros.
The module used one less storage word to store the 15 character string.
When your program transfers BCD values, be sure you know how the
data will be stored (how leading or trailing zeros will position data into
different storage addresses).
When formatting a message, you store the message text and you write
program logic to insert variables into your message. Consider the
message PRODUCED (quantity) PARTS. The message text is
PRODUCED....PARTS. The variable that you want to communicate is
the quantity. The variable can be timer or counter accumulated values,
analog I/O values, or any other data table word, byte, or bit that changes
value.
Format the message PRODUCED (quantity) PARTS as follows:
1. Create a file for your message using file A (source file) of a
file-to-file move instruction (FFM 060) in rung 17. Load your
message text (Table 3.N) into file A of FFM 060 starting with
position 001. Equivalent data table addresses are listed in the
left-hand column, the message is tabulated in the right-hand column.
Use the slash as your BCD delimiter.
Formatting a SingleĆLine
Message