Alarm Items (Reference) define individual tags or expressions monitored for alarm conditions within your FrameworX solution. Alarm Items are the fundamental alarm objects that:
- Monitor tag values against configured conditions
- Trigger alarm events when conditions are met
- Associate with AlarmGroups for shared behaviors
- Organize within AlarmAreas for hierarchical structure
- Support multiple limit values for shift-based operations
Each Alarm Item represents a single monitored condition that generates alarms based on your defined thresholds and settings.
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Configuration Properties
| Property | Description | Required |
|---|---|---|
| TagName | The tag being monitored for alarm events | Yes |
| Condition | Trigger condition (Hi, Lo, RateOfChange, etc.) | Yes |
| Limit | Primary threshold value | Yes |
| Limit1 | Secondary threshold (for shift-based limits) | No |
| Limit2 | Tertiary threshold (for shift-based limits) | No |
| Group | Associated AlarmGroup for shared properties | Yes |
| Area | AlarmArea for hierarchical organization | No |
| Priority | Alarm priority level | No |
| Message | Text displayed when alarm triggers | No |
| Disable | Enable/disable the alarm | No |
| Deadband | Range where changes are ignored | No |
| Setpoint | Target value for deviation alarms | No |
| SetpointDeadband | Range around setpoint to ignore | No |
| AuxValue | Additional information field | No |
| AuxValue2 | Secondary auxiliary value | No |
| AuxValue3 | Tertiary auxiliary value | No |
| Comment | Notes about the alarm item | No |
Alarm Conditions
| Condition | Description | Formula |
|---|---|---|
| Hi | High alarm | Tag ≥ Limit |
| HiHi | High-high alarm (auto-acks Hi) | Tag ≥ Limit |
| Lo | Low alarm | Tag ≤ Limit |
| LoLo | Low-low alarm (auto-acks Lo) | Tag ≤ Limit |
| RateOfChange | Rate exceeds limit | ΔTag/Δt ≥ Limit |
| DeviationMinor | Minor deviation from setpoint | |Tag - Setpoint| > Limit |
| DeviationMajor | Major deviation from setpoint | |Tag - Setpoint| > Limit |
| Equal | Exact match | Tag = Limit |
| GreaterThan | Greater than | Tag > Limit |
| GreaterEqual | Greater or equal | Tag ≥ Limit |
| LessThan | Less than | Tag < Limit |
| LessEqual | Less or equal | Tag ≤ Limit |
| Changed | Any change | Tag value changed |
| ChangedUp | Value increased | Tag value increased |
| ChangedDown | Value decreased | Tag value decreased |
| NotEqual | Not equal | Tag ≠ Limit |
Creating Alarm Items
- Navigate to Alarms → Items
- Enter TagName or select from tag list
- Select Condition type
- Set Limit threshold value
- Choose AlarmGroup for behavior
- Press Enter to save
Example configuration:
TagName: Tank1.Temperature
Condition: HiHi
Limit: 95
Group: Critical
Message: "Tank 1 Critical Temperature"
Priority: 100Shift-Based Limits
Use multiple limit values for different operational periods:
| Property | Usage |
|---|---|
| Limit | Default/primary threshold |
| Limit1 | Secondary threshold (e.g., day shift) |
| Limit2 | Tertiary threshold (e.g., night shift) |
Enable via Alarms → Global Settings → Enable LimitsByShift
Deadband Configuration
Prevents alarm chattering:
Value Deadband:
- Alarm triggers at Limit
- Must drop below (Limit - Deadband) to clear
- Must exceed (Limit + Deadband) to re-trigger
Setpoint Deadband:
- Applied around setpoint for deviation alarms
- Prevents minor fluctuations from triggering
Runtime Properties
Access alarm item state at runtime via @Alarm.Item.[ItemName]:
csharp
// Check alarm state
bool active = @Alarm.Item.HighTemp.Active;
DateTime activeTime = @Alarm.Item.HighTemp.ActiveTime;
// Get current values
double currentValue = @Alarm.Item.HighTemp.Value;
double limitValue = @Alarm.Item.HighTemp.Limit;Best Practices Checklist
- Use meaningful names - TagName should clearly identify the monitored point
- Set appropriate deadbands - Prevent alarm flooding from oscillating values
- Configure priority levels - Critical alarms get higher priority
- Write descriptive messages - Include context and severity in alarm text
- Group related alarms - Use AlarmGroups for common behaviors
- Document with comments - Use Comment field for maintenance notes
- Test conditions - Verify alarms trigger at expected values
Troubleshooting
Alarm not triggering:
- Verify TagName is valid
- Check Condition logic matches requirement
- Ensure not Disabled
- Confirm AlarmGroup is active
Excessive alarms:
- Increase Deadband value
- Review trigger Condition
- Check for tag oscillation
- Consider time deadband in AlarmGroup
Wrong threshold:
- Verify Limit value
- Check shift-based limits if enabled
- Confirm Setpoint for deviation alarms
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