Allen-Bradley controllogix 1756-L55M12 User Manual page 36

36 Communicate over Networks
Publication 1756-UM001G-EN-P - January 2007
The controller supports several ladder diagram (LD) and structured
text (ST) instructions to manipulate ASCII characters.
Read and Write ASCII Characters
Instruction Code Command
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
Create and Modify Strings of ASCII Characters
Instruction Code Command
CONCAT Add characters to the end of a string
DELETE Delete characters from a string
FIND Determine the starting character of a sub-string
INSERT Insert characters into a string
MID Extract characters from a string
Convert Data to or from ASCII Characters
Instruction Code Command
STOD Convert the ASCII representation of an integer value to a SINT,
INT, DINT, or REAL value
STOR Convert the ASCII representation of a floating-point value to a
REAL value
DTOS Convert a SINT, INT, DINT, or REAL value to a string of ASCII
characters
RTOS Convert a REAL value to a string of ASCII characters
UPPER Convert the letters in a string of ASCII characters to upper case
LOWER Convert the letters in a string of ASCII characters to lower case