Omron NT31 Operation Manuals page 426

Alarm List, Alarm History
- Alarm history in occurrence order
With an alarm history in occurrence order, when the status of the monitored
host bit changes to "1" (ON), the corresponding message becomes the latest
message (the messages are displayed from the oldest first or from the newest
first, depending on the memory switch setting made at the NT31/NT31C).
When the status of the bit changes back to "0" (OFF), the message remains
displayed.
If the statuses of multiple bits change to "1" (ON) at the same time, the bit
memory table with the smallest bit memory table number is given priority.
[Display from oldest record first]
- Since new messages are added at the end of the history, the displayed mes-
sages do not change. However, when the final page is displayed and a
message is added below it, the
to inform the operator that a message has been added.
[Display from the newest record first]
- New messages are added at the top of the history. When a message is add-
ed, the screen will switch to the display starting from the first message re-
gardless of the current display position.
S Alarm history in frequency order
With an alarm history in frequency order, when the status of a monitored host bit
changes to "1" (ON), the number of times that bit has changed to "1" (ON) is de-
termined and the display is changed to reflect the new descending order of fre-
quency of occurrence. When the bit status changes back to "0" (OFF), its fre-
quency display remains unchanged.
If there are bits with the same frequency of occurrence, the one whose bit
memory table has the smallest bit memory table number is displayed closest to
the top of the history.
- The display contents change in real time according to the frequencies of oc-
currence, but the display range does not change. The serial number (counting
from the top) of the message at the topmost position is retained until the dis-
play range is changed by touch switch operation.
S Lighting of the message display field and touch switches for scrolling
The message display field and touch switches for scrolling light as follows ac-
cording to the alarm list/history status.
- Message display field
When a message field is pressed for the first time after it is displayed, or
pressed after another message has been pressed, if image/library data is set
for the corresponding bit memory table, the message field lights (the corre-
sponding image/library data is also displayed at this time). This makes it pos-
sible to tell at a glance which message the displayed image/library data corre-
sponds to.
- Line scrolling touch switches
When there are messages above or below the displayed range, these touch
switches are lit. This makes it possible to tell at a glance whether there are any
messages outside the displayed range.
touch switch is displayed in reverse video
Section 7-11
415