Analog Level Alarm Tag

Help Contents

Introduction

The Analog Level Alarm Tag is a 4-limit analog alarm with high-high, high, low and low-low alarm limits.

Configuration Properties

The Analog Level Alarm Tag supports the configuration properties of the Data Point Alarm Tag plus these properties:

Property Type Version Description
SourceTag Reference 1.5 The source tag for this alarm.
Deadband LREAL 1.5 The deadband applied to each alarm limit to avoid alarm jitter.
HighHighLimit LREAL 3.12 The High-High alarm limit. When the source tag value is greater than or equal to this value, a High-High alarm is raised.

Note: This property can be changed by the operator using the AlarmPropertyOverride Tag Command.

HighHighMessage STRING 3.12 The text to display for the High-High alarm.
HighHighSeverity UINT 3.12 The severity of the High-High alarm. A value of zero disables the high-high alarm limit.
HighLimit LREAL 1.5 The High alarm limit. When the source tag value is greater than or equal to this value, a High alarm is raised.

Note: This property can be changed by the operator using the AlarmPropertyOverride Tag Command.

HighMessage STRING 1.5 The text to display for the High alarm.
HighSeverity UINT 1.5 The severity of the High alarm. A value of zero disables the high alarm limit.
NormalSeverity UINT 3.26 The severity of the analog level alarm in the normal state.
LowLimit LREAL 1.5 The Low alarm limit. When the source tag value is less than or equal to this value, a Low alarm is raised.

Note: This property can be changed by the operator using the AlarmPropertyOverride Tag Command.

LowMessage STRING 1.5 The text to display for the Low alarm.
LowSeverity UINT 1.5 The severity of the Low alarm. A value of zero disables the low alarm limit.
LowLowLimit LREAL 3.12 The Low-Low alarm limit. When the source tag value is less than or equal to this value, a Low-Low alarm is raised.

Note: This property can be changed by the operator using the AlarmPropertyOverride Tag Command.

LowLowMessage STRING 3.12 The text to display for the Low-Low alarm.
LowLowSeverity UINT 3.12 The severity of the Low-Low alarm. A value of zero disables the low-low alarm limit.

Data Properties

The Analog Level Alarm Tag supports the data properties of the Data Point Alarm Tag plus these properties:

Property Type Description
SourceTagValue LREAL The value of the source tag.
AlarmThreshold USINT The current alarm threshold.
  1. Normal
  2. High
  3. Low
  4. High-High
  5. Low-Low
TunedLimitMask BYTE A bitmask of the alarm limits that have been changed by the operator:
  1. The HighLimit has been overridden.
  2. The LowLimit has been overridden.
  3. The HighHighLimit has been overridden.
  4. The LowLowLimit has been overridden.
TunedLimitHigh LREAL The value of the HighLimit set by the operator. Note: This value is used only when Bit 0 of TunedLimitMask is set.
TunedLimitLow LREAL The value of the LowLimit set by the operator. Note: This value is used only when Bit 1 of TunedLimitMask is set.
TunedLimitHighHigh LREAL The value of the HighHighLimit set by the operator. Note: This value is used only when Bit 2 of TunedLimitMask is set.
TunedLimitLowLow LREAL The value of the LowLowLimit set by the operator. Note: This value is used only when Bit 3 of TunedLimitMask is set.

Tag Commands

The Analog Level Alarm Tag supports the tag commands of the Data Point Alarm Tag.

Relationships to Other Tag Types

The Analog Level Alarm Tag builds on the features of these tag types:

Further Information

Alarm Conditions

To learn about abnormal conditions in SCADA applications.

Core Driver

To learn about the Core Data Driver.

Glossary

For the meaning of terms used in Fernhill SCADA.