Chapter 3
Tag Configuration
3-36
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National Instruments Corporation
Figure 3-13.
Alarms for Bit Array Tag Configuration
String Tags
String tags have no alarm states based on tag value. They only support
Bad Status alarms.
What Is Alarm Deadband on Analog Tags?
Alarm Deadband is a method commonly used to avoid repetitive alarm
messages because of a tag value that hovers near the alarm limit. Alarm
Deadband defines how much a tag value must change from the alarm
limit before it is considered normal. For example, if a tag that represents a
temperature value hovers near an alarm limit of 40 degrees Celsius, the tag
might go in and out of alarm many times in a relatively short period of time.
Table 3-8 shows examples of events with Alarm Deadband set to 0.0%.
Table 3-8.
Events with Alarm Deadband = 0.0%
Time
Value
Event
Alarm Type
9:15:05
40.1
Yes
HI
9:15:10
39.9
Yes
Normal
