Rockwell Automation 1772-LS_LSP,D17726.8.6 PROG/OPER MANUAL-MINI PLC-2/05 User Manual
Page 208
Report Generation
Chapter 17
17-14
Message DeleteĆ MD
Accessible only in rung/program mode, the message delete command is
used to delete messages from memory. This command is accessed by
pressing [M][D][,]
The message delete command cannot be terminated before completion. It
self terminates after the message has been cleared from memory and a
MESSAGE DELETED prompt is printed. you can enter [ESC] or
[CANCEL COMMAND] to return to ladder diagram display.
Message IndexĆ MI
Accessible in any mode, the message index command prints a list of the
message numbers used and the amount of memory (in words) used for each
message. In addition, the number of unused memory words available
is listed.
The message index command is accessed by pressing [M][I][RETURN].
This command cannot be terminated before completion. It self-terminates
after the list is completed. To return to ladder diagram display,press [ESC]
or [CANCEL COMMAND].
Using Latch and Unlatch instructions, you can easily program automatic
report generation to handle multiple or simultaneous message requests.
Simultaneous requests are handled by a priority system-the lower the
message number, the higher the priority.
Figure 17.6 shows a sample program that you can use to activate each
message. When the event occurs which requests the message, the request
bit is latched. After the event has occurred and the message is printed (the
done bit comes on), the request bit is unlatched. This technique also
ensures the requested message gets printed once per request.
Figure 17.6
Example Program to Request a Message.
Event
Event
L
Request
Done
L
Request
We showed you how to generate messages that contain ASCII, graphic
characters, or variable data. The next chapter shows how to use several
special programming technique.
Example Programming
Chapter Summary