Alarms

GVA Alarms Service

The Alarms Service provides centralised alarm management for GVA systems. It enables systems to raise, acknowledge, and clear alarms while maintaining an auditable history.

Overview

The Alarms Service handles:

  • Collection of alarms from all GVA systems
  • Priority-based alarm display
  • Acknowledgement and clearance workflow
  • Alarm history and audit logging

Alarm Concepts

Alarm Severity

graph TB subgraph "Alarm Priorities" C[CRITICAL
Immediate action required] W[WARNING
Attention needed soon] A[ADVISORY
Information only] end style C fill:#d32f2f,color:#fff style W fill:#ff9800,color:#000 style A fill:#ffeb3b,color:#000

Alarm States

stateDiagram-v2 [*] --> Active : Raised Active --> Acknowledged : Operator ack Acknowledged --> Cleared : Condition resolved Active --> Cleared : Auto-clear Cleared --> [*] : Archived Active --> Active : Updated Acknowledged --> Active : Re-raised

Message Sequence

Alarm Lifecycle

sequenceDiagram participant Sys as Source System participant DDS as DDS Network participant Alm as Alarms Service participant HMI as HMI Display participant Op as Operator Note over Sys: Fault detected Sys->>DDS: Raise Alarm Note right of Sys: severity=WARNING
message="Engine temp high"
state=ACTIVE DDS->>Alm: Receive alarm Alm->>Alm: Store alarm Alm->>Alm: Update statistics DDS->>HMI: Alarm notification HMI->>HMI: Display alarm HMI->>Op: Audio alert Note over Op: Operator reviews Op->>HMI: Acknowledge alarm HMI->>DDS: Acknowledge DDS->>Alm: Update state Alm->>Alm: Record ack time Note over Sys: Fault resolved Sys->>DDS: Clear Alarm Note right of Sys: state=CLEARED DDS->>Alm: Update state Alm->>Alm: Record clear time DDS->>HMI: Update display HMI->>HMI: Remove from active list

Multiple Alarms

sequenceDiagram participant BMS as BMS participant NAV as Navigation participant WPN as Weapons participant DDS as DDS Network participant Alm as Alarms Service participant HMI as HMI Note over BMS,WPN: Simultaneous faults par Concurrent alarms BMS->>DDS: Raise Alarm (CRITICAL) Note right of BMS: "Comms lost" and NAV->>DDS: Raise Alarm (WARNING) Note right of NAV: "GPS degraded" and WPN->>DDS: Raise Alarm (ADVISORY) Note right of WPN: "Turret calibration due" end DDS->>Alm: Process alarms Alm->>Alm: Sort by priority Note over Alm: Order: CRITICAL first Alm->>HMI: Update alarm list HMI->>HMI: Display sorted list Note right of HMI: 1. Comms lost (CRITICAL)
2. GPS degraded (WARNING)
3. Turret cal due (ADVISORY)

Alarm Data

Alarm Structure

Field Type Description
alarmId string Unique alarm identifier
sourceSystem string System that raised the alarm
alarmCode string Alarm type code (e.g., "ENG_001")
severity enum CRITICAL, WARNING, ADVISORY
state enum ACTIVE, ACKNOWLEDGED, CLEARED
message string Human-readable description
raisedTime datetime When alarm was raised
ackTime datetime When alarm was acknowledged
clearedTime datetime When alarm was cleared
metadata map Additional alarm data

Severity Levels

Level Description
CRITICAL Immediate action required - safety or mission critical
WARNING Attention needed soon - degraded capability
ADVISORY Information - no immediate action needed

Alarm States

State Description
ACTIVE Alarm condition present
ACKNOWLEDGED Operator has seen alarm
CLEARED Alarm condition resolved

HMI Display

Alarm Popup Styles

The GVA HMI displays alarm popups with colour-coded severity indicators:

Warning Caution Advisory
Warning Caution Advisory
Critical/Warning Caution Advisory
Immediate attention required Operator awareness needed Informational

When multiple alarms are queued, the display indicates pending items:

Queued Alarms

Colour Coding

Severity Background Text Indicator
CRITICAL Red (#D32F2F) White Flashing
WARNING Orange (#FF9800) Black Steady
ADVISORY Yellow (#FFEB3B) Black Steady

Best Practices

Raising Alarms

  1. Use unique alarm codes - Define a code scheme (e.g., "SYS_TYPE_NNN")
  2. Clear messages - Operators need to understand the issue quickly
  3. Appropriate severity - Don't overuse CRITICAL
  4. Include context - Use metadata for values, thresholds, etc.

Managing Alarms

  1. Clear promptly - Don't leave stale alarms
  2. Update, don't duplicate - Update existing alarms rather than creating new ones
  3. Auto-clear when possible - Clear automatically when condition resolves

HMI Guidelines

  1. Sort by severity - CRITICAL always at top
  2. Time ordering - Within severity, show newest first
  3. Audio cues - Different sounds for different severities
  4. Acknowledgement - Require operator action for critical alarms

Troubleshooting

Alarms Not Appearing

  • Check DDS domain configuration
  • Verify Alarms topic name ("Alarms")
  • Ensure alarm service is running

Duplicate Alarms

  • Use consistent alarm IDs for same condition
  • Clear previous alarm before raising new one
  • Check for multiple instances of source system

Alarms Not Clearing

  • Ensure source system publishes CLEARED state
  • Check alarm ID matches original alarm
  • Verify network connectivity