User Manual PLC-3 FAMILY I/0 Instruction Manual

Programming DH and DH+
Message Procedures
Chapter 6
6-13
The scanner has its own command language that you can use in
programming message procedures. Table 6.D summarizes these
commands.
Table 6.D
Message
Procedure Commands
Command Format and Explanation See
page:
(assignment) destination = source
Assign a numeric value to a user symbol or copy data from the source to the
destination (see chapter 5).
CREATE C @system symbol$logical address
Create a symbolic address and equate it to a logical address.
614
DELETE D @system symbol
Delete a symbolic address or an entire message procedure from memory.
614
(execute) @system symbol
Execute the named message procedure.
615
EXIT E
Terminate execution of the current message procedure.
615
GOTO G label
Continue executing the current procedure from the point specified by the label.
615
IF I expression embedded command
Execute the embedded command only if the specified expression is true.
616
ON_ERROR O embedded command
Execute the embedded command only if an error occurs after this statement in
the procedure.
616
STOP S
Terminate execution of the message (MSG) instruction in the ladder program.
617
You can abbreviate each command to the letters shown in the format and
Explanation column of Table 6.D. We recommend that you use the
command abbreviations because they:
make the commands easier to program
save memory space
reduce execution time
You can insert spaces in command lines to make the message procedure
easier to read. However, you should keep spaces to a minimum, because
they use memory space and slow execution of the message procedure.
Message Procedure
Commands