TXP-C20_Instruction_Manual_(Rev1.0)
REV – 1.0
[34-2900-0207-5 ]
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Figure 3-3 – Channel Setup Screen
3.3.3
Alarm 1 / Alarm 2 / Alarm 3 Setup Menus
Alarms 1, 2 and 3 have identical menus. The only difference between each is A1 front panel LED indicators are
yellow while A2’s and A3’s are red. Typical applications often have A1 set at a WARN level, A2 at a HIGH level and
A3 at a negative FAULT level. However, it is important to understand there is no functional difference between A1,
A2 and A3. Since their configuration menus are identical, only one is shown in Figure 3-4.
Figure 3-4 – Alarm Setup Screen
•
Set Point
is entered in engineering units and determines the value where the alarm trips. For example, if a
channel monitors 0-50 ppmH2S and the desired alarm level is 10 ppm, the correct entry is 10.00. A one
percent dead band prevents alarm chatter. This means after tripping an alarm the input must move at least
1% of full scale back through the setpoint for the alarm to auto reset.
•
The
ON Delay / OFF Delay
entries allow
ON
and
OFF
time delays affecting how long the trip-point must be
surpassed before an alarm event transition occurs.
ON
delays are limited to 10 seconds while
OFF
delays
may be as long as 120 minutes. Delays are useful in many applications to prevent nuisance alarms and
unwanted cycling into and out of alarm conditions.
•
Low Trip
is set for
NO
for increasing alarms or
YES
for decreasing alarms to determine if the alarm activates
upon exceeding or falling below the set-point.
•
Latching
determines either manual or automatic alarm reset operation.
YES
requires a manual Alarm Reset
to unlatch the alarm even though an alarm condition no longer exists.
YES
also causes this alarm’s common
