Rockwell Automation 2706 DL40 HARDWARE USER MANUAL - Manual (Page 33)

Chapter 3
The Run Mode – Remote I/O
3 – 7
Communications Method Words Consisting Of
Discrete I/O – 1 /
4
Rack 17 1 word & Priority Message
Discrete I/O – 1 /
2
Rack 49 3 words & Priority Message
Discrete I/O – 3 /
4
Rack 81 5 words & Priority Message
Discrete I/O – Full Rack 113 7 words & Priority Message
Block Transfer 497 31 words & 1 Priority Message
See Chapter 10 for more information.
Note: Unlike the Message/Variable/Slave Run Mode, you cannot send
variables to be included in a message.
The Bit Trigger table has three sections (all three sections are sent with a
single transfer):
Priority Message Number Section
When a priority message trigger is received (via Remote I/O, RS-485 or
Keyboard Port), it is queued as in the Message/Variable/ Slave Run Mode.
When the message that is currently displayed finishes running, all Priority
Messages in the queue will be run.
•
If no bits in either the Priority Section or the Round Robin section have
been changed, the DL40 will return to where it left off (in either section)
and resume running messages.
•
If any bit in either the Priority Section or the Round Robin section has
been changed, the DL40 will return to the start of the Priority Section to
resume running messages.
The Priority message can be any message even a Special Message. Send the
number of the message you want to trigger in the Priority Message Number
Section of the Bit Trigger Table. See page 10-24. If you don’t want to trigger
a priority message, leave this part of the table empty (i.e.
= 0).
Priority Section
Messages in this section are prioritized, starting with Message Number 1
(corresponding to bit 00 of Word 1). This message has the highest priority.
The message with the highest priority (that has its corresponding bit set) will
be displayed first. After the highest priority message has completed running,
the message with the next highest priority (with its bit set) will be displayed.
The DL40 will continue to run through the Priority Section displaying
messages until the message corresponding to the last set bit in this section
has been displayed.
Messages are displayed only once for each change to the Bit Trigger table. If
an updated table (with a new Priority Message Number or at least one bit in
either the Priority Section or the Round Robin Section changed) is sent to the
DL40, the messages of the new Bit Trigger Table will begin to run
immediately even if messages in the old Bit Trigger Table were not run. It is