Dynamic Chaining - Allen-Bradley A-B QUALITY DL20 Series User Manual

Dynamic Chaining

Dynamic chaining allows the DL20 to continuously repeat a sequence of
messages over and over again. These may be fault or status messages that
have been triggered over a period of time.
Select dynamic chaining using the Set Up Master special function as
described in Chapter 8. With dynamic chaining enabled, messages are
displayed as they are triggered. These messages are displayed continuously
according to the selected attributes (scroll or line mode, wait time, etc.).
The dynamic chaining queue capacity is 20 message triggers. If the queue
capacity is reached, any following message triggers are ignored until the
queue is cleared. Clear the message queue by triggering any of the following
special messages described earlier in this chapter:
Special Message #2 - Clears Display and Queues
Special Message #9 - Clears Queues and Halt Run Mode
Special Message #10 - Clears Queues
The order in which message triggers are displayed may not be the same as
the order in which they were actually triggered. However, you can use
special messages #8 and #9 with dynamic chaining so that messages are
displayed in the exact same order as triggered. The sequence would be:
1. Trigger special message #9. This causes the display to stop unqueuing
messages and empties the message and data queues.
2. Send other message triggers (up to 20). They are stored in the queue.
3. Trigger special message #8 to begin unqueing and repetitive display of
these messages.
4. Messages are displayed continuously, until special message #9 is
triggered.
5. Trigger special message #9, you will be able to reload the message queue
with new message triggers.
6. The process can be repeated.
Note: Do not use messages with variable data when using dynamic
chaining.
Chapter 5
Run Mode
5–13