Rockwell Automation 2706-MB1 MESSAGEVIEW 421 SOFTWARE MANUAL - Manual (Page 230)

10–22 Terminal and Communication Setup
Publication 2706-817
The Bit Trigger tag is the base address for a table that contains up to
1024 bits (64 words). Specific messages are assigned one bit as their
bit trigger. The terminal scans the bit table and triggers the message
whose bit corresponds to the lowest set bit in the table.
This tag is required if at least one message in the application has a bit
trigger assigned and enabled.
The only valid data type for this tag is unsigned integer.
Note: An ASCII Triggering device does not support bit triggers.
The Return Number tag is the address where the terminal writes the
message number of the most recent active message on the display,
provided:
•
the message has no function keys enabled, and
•
Acknowledge is not enabled, and
•
the Return Message Number attribute is enabled in the Advanced
tab dialog.
The only valid data type for this tag is unsigned integer.
Note: If the controller is an ASCII Triggering device, the Return
Message Number is sent back as part of the Ctrl-N message. See
Page 5–12.
To enter these global Message Tags:
•
select the name of a tag from the list box, or
•
type a new tag name and select the Edit Tag button to define the
tag.
To edit the Message Tag attributes:
1. Put the insertion pointer in the tag box.
2. Select the Edit Tag button to bring up the Tag Form dialog: