Rockwell Automation 1771-DA,D17716.5.13 U MNL 1771-DA ASCII I/O MODULE User Manual
Page 110
ASCII I/O Module Tutorial
Chapter 4
4Ć36
String Length Less Than Module's String Length, Right Justified
Whenever the ASCII module receives an end-of-string delimiter from the
ASCII device, it transfers the data in its input buffer to the processor. You
will enter a data string less than the set string length as determined by
IW2(00-13). You will also observe how the data is stored in the data table
file.
1.
Enter: 12345[ENTER]
Procedure P1
Connect the 1770ĆCB cable, and set your industrial
terminal to alphanumeric mode (check parameters)
•
Initialize the module by changing PLCĆ3 operation mode
3[ENTER]2[ENTER]
Procedure P2
Enter your data
Procedure P3
Connect the 1775ĆCAT cable, and set your industrial
terminal to PLCĆ3 mode
Procedure P4
Observe how the data string is stored in data table file O6.0
Refer to the procedures in section titled “Reading Data From Your ASCII
Device” (P. 1-10).
RADIX = %A START = WO006:0000
WORD #
00000
0
00H00H
1
00H00H
2
3
4
5
6
7
00010
2 3
4 5
00H00H 00H00H 00H00H 00H00H 00H00H 00H00H
RADIX = %H START = WO006:0000
WORD #
00000
0
0000
1
0000
2
2020
3
2020
4
2020
5
2020
6
2020
7
2031
00010
3233
3435
0000
0000
0000
0000
0000
0000
Results The file displays the five character string in ASCII or in hex,
respectively. The data is right justified.
Notice the following:
The data string of five characters was transferred when you entered the
end-of-string delimiter.
The end-of-string delimiter was not transferred to the data table.
The module added fill characters, blank in ASCII or 20 in hex, in
display words 2, 3, 4, 5, and 6 to complete the string.
The data was right justified.