Rockwell Automation Allen-Bradley ControlLogix 1756-L Series, User Manual

Page: 214 / 307

Publication 1756-UM001A-EN-P - September 2000
17-6 Communicate with an ASCII Device
D. If you are using the AWA instruction, type the character(s) to
append to the data.
For the ASCII code of a character, refer to
the back cover of this manual.
E. If the ASCII device is configured for XON/XOFF flow control,
select the
XON/XOFF check box.
F. If the ASCII device is a CRT or is pre-configured for half duplex
transmission, select the
Echo Mode check box.
G. Select the Delete Mode:
H. Click OK .
To read or write ASCII characters, use the ASCII Serial Port
instructions. See the
Logix5000 Controllers General Instruction Set
Reference Manual , publication 1756-RM003.
To append: Then: Notes:
one character 1. In the Append Character 1 text
box, type the hexadecimal
ASCII code for the first
character.
2. In the Append Character 2 text
box, type
$FF
.
For printable
characters, such
as 1 or A, type the
character.
two characters In the Append Character 1 and 2 text
boxes, type the hexadecimal ASCII
code for each character.
If the ASCII device is: Select: Notes:
CRT CRT
•
The DEL character ($7F) and the character that precedes the DEL
character are
not sent to the destination.
•
If echo mode is selected and an ASCII instruction reads the DEL
character, the echo returns three characters: BACKSPACE SPACE
BACKSPACE ( $08 $20 $08).
printer Printer
•
The DEL character ($7F) and the character that precedes the DEL
character are
not sent to the destination.
•
If echo mode is selected and an ASCII instruction reads the DEL
character, the echo returns two characters: / ($2F) followed by
the character that was deleted.
None of the above Ignore The DEL character ($7F) is treated as any other character.