User manual
66 Rockwell Automation Publication 1769-UM011I-EN-P - February 2013
Chapter 4 Communicate over Networks
5. Click the User Protocol tab.
6. From the Protocol pull-down menu, choose ASCII.
7. Specify ASCII settings.
The controller supports several instructions to manipulate ASCII characters.
The instructions are available in ladder diagram (LD) and structured text (ST).
Read and Write ASCII Characters
Create and Modify Strings of ASCII Characters
Instruction Code Description
ABL Determine when the buffer contains termination characters
ACB Count the characters in the buffer
ACL Clear the buffer
Clear out ASCII Serial Port instructions that are currently executing or are in the queue
AHL Obtain the status of the serial port control lines
Turn on or off the DTR signal
Turn on or off the RTS signal
ARD Read a fixed number of characters
ARL Read a varying number of characters, up to and including the first set of termination characters
AWA Send characters and automatically append one or two additional characters to mark the end of
the data
AWT Send characters
Instruction Code Description
CONCAT Add characters to the end of a string
DELETE Delete characters from a string
FIND Determine the starting character of a substring
INSERT Insert characters into a string
MID Extract characters from a string