Omron NT31 Operation Manuals page 418

Alarm List, Alarm History
S Differences between alarm list and alarm history
The alarm list and alarm history differ in the following respects.
Item Alarm List
Display As element only
method
Monitored Host bits allocated
data to bit memory
tables within the
designated range
Monitor While the alarm list
timing element is dis-
played only
Recording No recording exe-
cuted
Message When a message
contents is displayed for an
alarm list, the con-
tents of the charac-
ter string memory
table set for the bit
memory table are
read.
Output Not possible for
data to there is no record
the Sup- data
port Tool
Display Ascending order of
order bit memory table
numbers
Alarm History
As element, and as a screen displayed from the
System Menu
Host bits allocated to bit memory tables for which
"History" is set.
Continuous monitoring regardless of the displayed
screen
Time of occurrence is recorded.
- Occurrence order:
When the status of a monitored bit at the host
changes to "1" (ON), the contents of the charac-
ter string memory table set for the bit memory
table are read.
- Frequency order:
When a message is displayed for an alarm his-
tory, the contents of the character string memory
table set for the bit memory table are read.
Possible (occurrence order and frequency order
records transmitted simultaneously)
Select either of the following:
- Occurrence order:
Chronological order in which the statuses of the
monitored bits changed to "1" (ON) (displayed
from the oldest record first or the newest record
first depending on the memory switch setting at
the NT31/NT31C)
- Frequency order:
Order based on the number of times the status
of each bit has changed to "1" (ON), from most
to least frequent.
Section 7-11
407