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2-16
Section
Special Functions
239
Occurrence Order
The records are displayed in the order in which the status of the set bit memory
tables (bits) changed to 1 (ON). Whether the records are displayed from the old-
est first or from the newest first is set with the memory switches at the PT.
Frequency Order
The records are displayed in the order of the number of times the statuses of the
bit memory tables have changed to 1 (ON).
Checking The Record in The Maintenance Mode
Select the Maintenance mode from the System Menu and display the alarm his-
tory record.
For details on the System Menu operation, refer to section 6 of the
Setup Manu
-
al.
When the record is checked in the Maintenance mode, screens like those shown
below are displayed. (The following examples show NT31/NT31C PTs.)
Occurrence Order Screen
Frequency Order Screen
Checking The Record During Operation
The alarm history can be checked during operation by displaying a screen for
which an alarm history element has been registered.
In this case, the alarm history element is displayed in the manner shown below.
However, note that the width and height of the alarm history element, and the
method of display for the time, can be changed by setting properties. For details,
refer to
2-11 Alarm List, Alarm History (page 173).
Occurrence Order Screen
Check the remote I/O
transmission line!
Abnormal remote I/O
06/06
16:02
Abnormal high function unit
06/07
09:21
Cycle time over
06/17
15:44
Occurrence of
transmission
abnormality
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Summary of Contents for NT21 Series
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