Omron NT31 Operation Manuals page 425

Alarm List, Alarm History
414
S Timing of message reading
For alarm lists and alarm histories in frequency order, when a message is dis-
played, scrolling, or screen switching, the character string memory table set for
the bit memory table is read, and the latest message is displayed.
In contrast, in the case of alarm histories in occurrence order, only when the sta-
tus of the allocated bit of the bit memory table changes to "1" (ON), the character
string memory table set for the bit memory table is read and its contents are re-
corded. Accordingly, even if the contents of the character string memory table
change later, the displayed message will be kept the recorded contents. Howev-
er, if the status of another monitored host bit changes to "1" (ON) while an alarm
history in occurrence order is being displayed, the latest message at that point is
displayed.
S Display at message update
When the status of a monitored host bit changes during display of an alarm list/
alarm history, the display changes as follows.
- With an alarm list
With an alarm list, when the status of a monitored host bit changes to "1" (ON),
the corresponding message is displayed, and when it changes back to "0"
(OFF), the message is cleared (the messages are displayed in ascending or-
der of bit memory table numbers).
[When a message is added]
- If a message is added outside the display range (before or after the display
range), there is no change in the messages being displayed.
- If a message is added within the display range, the new message is dis-
played, and the messages following it are shifted one line downward.
[When a message is deleted]
- If a message is deleted outside the display range (before or after the display
range), there is no change in the messages being displayed.
- If a message is deleted within the display range, the messages following it
are shifted one line upward, except when it is the topmost message in the
display that is deleted, in which case the message immediately preceding
the present display range is displayed in its place.
If all the displayed messages are deleted at the same time, messages are
displayed starting with a message with the same serial number (counting
from the top) as the topmost of those that were displayed. (For example, if
the previous display started from serial number 7, the new display will also
start from a message with serial number 7.)
Section 7-11