Allen-Bradley SLC 500

QUICKDESIGNER ASCII Protocol •
••
• 253
If you typed the command string from an ASCII terminal, this is the response from the target display.
Note the zero value between the value 43 and 24.
⇑12,43,,24.
The following example is a BASIC statement that will read 4 variables, beginning with variable ID 1.
PRINT#1,CHR$(18);1;",";4;CHR$(13)
The first part of the BASIC statement is CHR$(18). The ASCII character 18 is equivalent to a
CONTROL-R. The next section of code is the character 1, which is the starting variable ID number. (,)
is a required delimiter. (4) is the number of variables to read. The last section of the code string is
CHR$(13). The ASCII character 13 is equivalent to a CARRIAGE RETURN.
Writing to Variables
The format for the command to write to a variable is:
(^V) (Variable ID number) (,) (value 1) (,) (value 2) (,)... (value N) (^M)
(^V) is the combination of the CTRL key and the V key pressed together. This key combination
produces a code equivalent to 16 hex or 22 decimal. (Variable ID number) is the ID number of the first
variable to be written. (,) is a required delimiter. (value 1) is the value to be written to the starting ID.
(value 2) is the next data value to be written to the next variable. (^M) is a CARRIAGE RETURN
which indicates the end of the ASCII string. A CARRIAGE RETURN code is equivalent to 0D hex or
13 decimal.
The format for writing two data values, starting with ID 2 is:
^V2, 767, 325 ^M
The following example is a BASIC statement that will send an ASCII string to write 2 data values,
starting with variable ID 2.
PRINT#1,CHR$(22);2;",";767;",";325;CHR$(13)
The first part of the BASIC statement is CHR$(22). The ASCII character 22 is equivalent to a
CONTROL-V. The next section of code is the character 2, which is the starting variable ID number. (,)
is a required delimiter. (767) is the value to be written to the starting ID. (325) is the next data value to
be written to the next variable. The last section of the code string is CHR$(13). The ASCII character 13
is equivalent to a CARRIAGE RETURN.