Rockwell Automation 2706-MB1 MESSAGEVIEW 421 SOFTWARE MANUAL - Manual (Page 160)

7–39 Creating Messages
Publication 2706-817
Freeze
Use the Freeze check box to keep display variables at the value they
had when their message was triggered. If the Freeze attribute is
disabled the terminal continually updates display variables as long as
the message is displayed.
Note: The value sent to the Historical Event Stack (if the HE Stack
attribute is enabled) is the value at the moment of triggering.
Historical Event Stack
Use the HE Stack check box to enable this attribute. The message
will be logged into the Historical Event Stack file each time it is
triggered.
The logged message includes the time and date when the message is
triggered, and the value in each display variable at the moment it is
triggered. See Page 4–19 for a discussion of the Historical Event
Stack.
Acknowledge Time
The Ack Time attribute may be used to log into the HE stack with
the message, the time and date when the message was acknowledged
if both the following apply:
•
the message requires the operator to press the ACK key on the
terminal, and
•
the HE Stack attribute is enabled.
Acknowledgeable Message
Messages may be defined as acknowledgeable messages which
require operator intervention.
Acknowledgeable messages remain displayed (active) until the
terminal operator presses the
ACK key and the preset acknowledge
hold time (50 ms) has expired. The bit at the global Acknowledge
tag address is set. The controller program checks this bit to make
sure the terminal operator has pressed the key before triggering
another message.
Use the Ack check box to define a message as acknowledgeable.
When Ack is enabled, Wait Time is overridden.