Alarms Module (Reference)

Module Components

Configuration Sections

Configuration Workflow

Runtime Architecture

Alarm Lifecycle

• Normal - No alarm condition
• Active - Condition triggered
• Acknowledged - Operator confirmed
• Normalized - Condition cleared, awaiting ack
• Return - Back to normal state

Execution Control

• Run/Pause/Stop alarm evaluation
• Monitor active alarm counts
• View performance metrics

Alarm Namespace

Access alarm objects at runtime:

csharp

// Alarm Items
bool isActive = @Alarm.Item.HighTemp.Active;
DateTime activeTime = @Alarm.Item.HighTemp.ActiveTime;

// Alarm Groups  
int criticalCount = @Alarm.Group.Critical.ActiveCount;
bool ackRequired = @Alarm.Group.Critical.AckRequired;

// Alarm Areas
@Alarm.Area.Production.AckAll();
int areaCount = @Alarm.Area.Production.AlarmCount;

// Global Settings
@Alarm.GlobalSettings.AuditTrail.AddCustomMessage("Event logged");
bool auditEnabled = @Alarm.GlobalSettings.AuditTrail.IsEnabled;

Key Concepts

AlarmItem

Individual monitored condition with:

• Tag reference
• Trigger condition (Hi, Lo, RateOfChange, etc.)
• Limit values
• Associated group and area

AlarmGroup

Collection sharing common properties:

• Acknowledgment requirements
• Notification methods
• Sounds and colors
• Logging preferences

AlarmArea

Hierarchical organization structure:

• Plant/process area grouping
• Filtering and navigation
• Area-based operations

Global Settings

System-wide configuration:

• Database connection
• Startup behavior
• Audit trail
• Shift-based limits

Display Integration

AlarmViewer Control

• Real-time alarm display
• Sorting and filtering
• Acknowledgment interface
• Historical view

AlarmArea Control

• Hierarchical navigation tree
• Area-based filtering
• Visual alarm indicators

Configuration example:

xml

<AlarmViewer>
  <List>OnlineAlarms</List>
  <AreaFilter>Production.Line1</AreaFilter>
  <ShowAcknowledged>false</ShowAcknowledged>
</AlarmViewer>

Notification Methods

Built-in Notifications

• Visual alerts in displays
• Sound alerts (configurable per group)
• Database logging

Custom Notifications

Via Script Classes:

csharp

public void SendAlarmNotification(AlarmEventArgs args)
{
    // Email notification
    EmailService.Send(args);
    
    // SMS alert
    SMSService.Alert(args);
    
    // External system
    SCADA.LogAlarm(args);
}

Audit Trail

Configuration

1. Enable in Global Settings
2. Select events to log
3. Configure retention period

Custom Messages

csharp

@Alarm.GlobalSettings.AuditTrail.AddCustomMessage(
    message: "Batch started",
    areaName: "Production",
    objectName: "Reactor1",
    value: "Batch#123"
);

Compliance Features

• User logon/logoff tracking
• Operator action logging
• Tag change recording
• System event capture

Database Configuration

Supported Databases

• SQLite (default)
• SQL Server
• PostgreSQL
• MySQL
• Oracle

Schema

• AlarmEvents - Active alarm records
• AlarmHistory - Historical alarm data
• AuditTrail - Audit log entries

Maintenance

• Set retention period (Life Time)
• Regular archival recommended
• Index optimization for performance

Best Practices

Design

1. Group strategically - Use groups for common behaviors
2. Build logical hierarchy - Areas match plant structure
3. Set appropriate limits - Avoid nuisance alarms
4. Use deadbands - Prevent alarm flooding
5. Configure priorities - Critical alarms stand out

Operations

1. Test notifications - Verify all alert methods
2. Train operators - Clear acknowledgment procedures
3. Regular review - Analyze alarm performance
4. Maintain database - Archive historical data
5. Document settings - For compliance audits

Performance

1. Optimize conditions - Simple expressions perform better
2. Batch operations - Group related alarms
3. Manage retention - Balance history vs storage
4. Monitor metrics - Track evaluation performance

Troubleshooting

Common Issues

Alarms not triggering:

• Verify tag values
• Check enable conditions
• Confirm group active
• Review deadband settings

Database issues:

• Check connection string
• Verify permissions
• Monitor disk space
• Review retention settings

Performance problems:

• Reduce evaluation frequency
• Optimize complex conditions
• Increase deadbands
• Archive old data

Notification failures:

• Verify script methods
• Check sound file paths
• Review email configuration
• Test network connectivity

Advanced Topics

For deep technical understanding: → See [Alarms Engine (Reference)]

For monitoring runtime performance: → See [Alarms Monitor (Reference)]

For custom sound configuration: → See [Alarm Groups Sounds]

For email notifications: → See [Alarm Email Notifications]

Alarms → Tutorial | Concept | How-to Guide | Reference

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