User Manual PLC-3 FAMILY I/0 Instruction Manual

Programming DH and DH+
Message Procedures
Chapter 6
6-2
The general steps for editing a DH or DH+ message procedure are:
1. Create and edit the ladder program containing message instructions
that control execution of the message procedure.
2. Allocate memory to the necessary data files.
3. Create and edit the message procedure.
You can perform these steps through your programming terminal. Refer to
its user’s manual for detailed information on creating and editing the
ladder program.
You can also perform the third step through an RS-232-C data terminal
connected to an RS-232-C channel on a Peripheral Communication
Module (cat. no. 1775-GA).
Table 6.A gives an example of how to edit the message instruction in the
ladder program. For more details on ladder-program editing, refer to the
user’s manual for your programming device.
Table 6.A
Entering
the Message Instruction into the Ladder Program
Prompt (if any) Action
Start editing session.
Insert a new rung.
Enter the bit that conditions the message rung.
Enter the message instruction.
ENTER FILE
ADDRESS
Enter the address of the file where the message resides in
memory. This file should be binary.
ENTER SYSTEM
ADDRESS OR
SYMBOL
Enter the channel designation for the scanner:
For example, E2.3.4:
• E2 is the module status
• 3 is the scanner module type
• 4 is the thumbwheel number
ENTER MESSAGE
TYPE
Enter the message type. This is always 1.
Enter a single assignment command or the name of a message
procedure. In this case, the message procedure name is PROC1.
End the editing session.
Editing the Message
Instruction