Rockwell Automation 1794-L34 FlexLogix Controller System User Manual User Manual
Page 37

Publication 1794-UM001G-EN-P - January 2007
Communicate over Networks 37
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
If you want to:
Use this instruction:
determine when the buffer contains termination characters
ABL
count the characters in the buffer
ACB
clear the buffer
ACL
clear out ASCII Serial Port instructions that are currently
executing or are in the queue
obtain the status of the serial port control lines
AHL
turn on or off the DTR signal
turn on or off the RTS signal
read a fixed number of characters
ARD
read a varying number of characters, up to and including the
first set of termination characters
ARL
send characters and automatically append one or two
additional characters to mark the end of the data
AWA
send characters
AWT
If you want to:
Use this instruction:
add characters to the end of a string
CONCAT
delete characters from a string
DELETE
determine the starting character of a sub-string
FIND
insert characters into a string
INSERT
extract characters from a string
MID