Rockwell Automation 2706-MB1 MESSAGEVIEW 421 SOFTWARE MANUAL - Manual (Page 221)

10–13 Terminal and Communication Setup
Publication 2706-817
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ATTENTION: When this global attribute is selected,
be certain that if block transfer is used:
The Acknowledge bit tag is assigned to the same block
as the Return Message Number tag.
Function Key write tags are assigned to the same block
as the Return Message Number tag,
The Function key Return Message Number is sent to the controller
twice:
•
when the message is displayed
•
when the Function key is pressed and released.
If the controlling device is an ASCII Triggering device the Function
key Return Message Number is sent back as part of the Ctrl-F
command. See Page 5–11.
The Acknowledge Return Message Number is sent to the controller
twice:
•
when the message is displayed
•
when the ACK key is pressed and released.
If the controlling device is an ASCII Triggering device the
Acknowledge Return Message Number is sent back as part of the
Ctrl-K command. See Page 5–11
If the Return Message Number option is disabled, messages that
require operator input may need individual notification and
handshake tags.
Note: A message with the Hidden Message attribute set will not
return its number to the controlling device, since it is not displayed.
Enable Message Queue
The Message Queue in the MessageView 421 terminal stores
value-triggered messages until the line(s) in which they will be
displayed is available. Bit-triggered messages are not queued.
•
If this option is enabled, up to 64 messages can be queued on a
First In – First Out basis. They are displayed in turn as terminal
display lines become available.
With this option enabled, make sure to define a Value Trigger tag
in the Control Tags tab dialog. See Page 10–23.
•
If this option is disabled, a message is displayed only if the line
assigned to it is available when it is triggered.