Rockwell Automation 2706-LV2P_LV2R_LV4P_LV4R DL40 PLUS USER MANUAL - Manual (Page 126)

Remote I/O Communications 8–34
Publication 2706-6.1
Round Robin Section
Messages with trigger bits set in this section are run after the priority
message and all messages in the Priority Section with bits set have
run. The DL40 Plus runs through this section displaying messages.
After the last message in this section is displayed, the DL40 Plus
returns to the first message (in this section) and starts again.
Messages continue to run until an updated Bit Trigger Table is sent.
After all priority messages in the updated Bit Trigger Table have run,
the DL40 Plus returns to where it left off in the Round Robin Section
and continues on from there.
Length of the Round Robin Section in (16 bit) words is:
•
the length of the Bit Trigger Table (32 words)
•
minus the Priority Message (1 word)
•
minus the length of the Priority Section (X words)
Note: The lengths of the Priority Message, the Priority Section, and
Round Robin Section are always in full (16 bit) words.
For example, If the Priority Section is 9 words long, then the length
of the Round Robin Section would be:
32 words
-1 word
-9 words
= 22 word s
In this mode, you can also:
•
Return the message number of the displayed message to a PLC.
This is automatically done in the Remote I/O scan.
•
Insert ASCII Input data into a message. Same as
Message/Variable/Slave run mode; except only returns data to a
PLC via RS-485/RS-232 Port. Note: Data is sent to Historical
Events Stack only if the Historical Event Stack Attribute is set.
•
Send DL40 Plus’s Real Time Clock or date data to a PLC. Same
as Message/Variable/Slave run mode.
•
Place messages on the Historical Events Stack. Same as
Message/Variable/Slave run mode but the Bit Image Table is put
on the stack each time it changes regardless of whether or not the
stack attribute is set. Note: If the message’s Historical Events
Stack attribute is set, message data is placed on the stack.
•
Send Messages to the Slave Address specified as a message
attribute. If the message’s print attribute is set, the message is
printed once for each time it is displayed or redisplayed. Note:
To send a message to a slave, the Port Use of the RS-485 or
RS-232 Port must be set to DL Slaves. Refer to Chapter 6, Serial
Port Communications, for more information.