INDI Safety Monitor Driver

Overview

The Safety Monitor driver aggregates safety status from multiple INDI devices and reports the worst-case condition. This allows observatory automation systems (like Ekos) to make informed decisions about dome operations, mount parking, and other safety-critical actions.

Key Features

  • Multi-Device Monitoring: Monitor safety status from multiple devices simultaneously
  • Event-Driven: Real-time updates via INDI client callbacks (no polling)
  • Flexible Connection: Support for local and remote devices
  • Dynamic Configuration: Add or remove devices without driver restart
  • Override Capability: Emergency override switch for manual control
  • Human-Readable Logging: Status changes reported as “Ok”, “Busy”, “Alert” instead of numbers

SAFETY_STATUS Standard Property

The Safety Monitor relies on the SAFETY_STATUS standard property, which any INDI driver can implement:

  • Property Name: SAFETY_STATUS
  • Type: Light Property
  • Element: SAFETY
  • States:
    • IPS_OK - Safe for operations
    • IPS_BUSY - Warning condition
    • IPS_ALERT - Unsafe/critical condition
    • IPS_IDLE - Unknown/disconnected

Compatible Devices

Any INDI driver implementing the SAFETY_STATUS property can be monitored. This includes:

Weather Drivers

All weather drivers automatically expose SAFETY_STATUS (mirrored from WEATHER_STATUS):

  • OpenWeatherMap
  • Weather Meta
  • Weather Simulator
  • And all other weather drivers

Power Devices

  • UPS Driver (battery charge monitoring)
  • Power supply drivers

Custom Devices

Any driver can implement SAFETY_STATUS for application-specific safety monitoring

Configuration

Connection String Format

Device connections are specified as a comma-separated list in the CONNECTION_STRINGS property:

DeviceName, DeviceName@host, DeviceName@host:port

Format Details:

  • Device name only: Uses localhost:7624 (default INDI port)
  • Device@host: Uses specified host, port 7624
  • Device@host:port: Fully specified connection
  • Multiple devices: Separate with commas
  • Spaces in names: Supported (no quotes needed)

Examples

Local devices only:

Open Weather Map, UPS

Mix of local and remote:

My Weather Station, UPS@localhost:7624, Remote [email protected]

All remote with custom ports:

[email protected]:7624, [email protected]:7625, Power [email protected]:7624

Operation

Safety Status Property

The driver creates a dynamic SAFETY_STATUS property with one element per monitored device:

SAFETY_STATUS
├─ Open Weather Map: Ok
├─ UPS: Busy  
└─ Power Supply: Ok

The overall property state (not individual elements) represents the worst case:

  • If all devices are Ok, overall state is Ok
  • If one device is Busy, overall state is Busy
  • If any device is Alert, overall state is Alert

Override Switch

The SAFETY_OVERRIDE switch forces the overall status to Ok regardless of actual device states:

  • Use Case: Emergency situations requiring manual control
  • Warning: When enabled, the driver logs a warning and sets the switch to Busy state
  • Recommendation: Disable as soon as the emergency condition is resolved

Dynamic Reconfiguration

Changes to CONNECTION_STRINGS take effect immediately:

  1. All existing client connections are closed
  2. New connections are established based on updated string
  3. SAFETY_STATUS property is rebuilt with new device list
  4. No driver restart required

Integration with Observatory Automation

Ekos Integration

Ekos Observatory module monitors the SAFETY_STATUS property to make go/no-go decisions:

  • Safe (IPS_OK): Observatory can operate normally
  • Warning (IPS_BUSY): Issue warnings, may continue with caution
  • Unsafe (IPS_ALERT): Emergency shutdown:
    • Stop mount tracking
    • Park mount
    • Close dome
    • Stop all automated sequences

Client Usage

INDI clients should monitor the overall property state, not individual element states:

# Pseudocode
safety_property = device.get_property("SAFETY_STATUS")

if safety_property.state == IPS_OK:
    # Safe to operate
elif safety_property.state == IPS_BUSY:
    # Warning condition
elif safety_property.state == IPS_ALERT:
    # Unsafe - take protective action

Example Scenario

Observatory Setup:

  • Weather station monitoring cloud coverage and wind
  • UPS monitoring power supply
  • Remote power controller monitoring mains power

Configuration:

CONNECTION_STRINGS: Weather Station, UPS, Power [email protected]

Scenario Timeline:

  1. Normal Operation (All Ok)
    • Weather: Clear skies, calm wind → Ok
    • UPS: Battery at 100%, on mains → Ok
    • Power: Mains stable → Ok
    • Overall Status: Ok ✓
  2. Warning Condition (One device Busy)
    • Weather: Increasing clouds → Busy
    • UPS: Battery at 100%, on mains → Ok
    • Power: Mains stable → Ok
    • Overall Status: Busy ⚠️
    • Action: Ekos issues warning, continues with caution
  3. Critical Condition (One device Alert)
    • Weather: Heavy clouds, unsafe → Alert
    • UPS: Battery at 30%, on battery → Busy
    • Power: Mains failed → Alert
    • Overall Status: Alert 🛑
    • Action: Ekos initiates emergency shutdown

Implementing SAFETY_STATUS in Your Driver

To make your driver compatible with Safety Monitor:

1. Add the Property 

// In your driver header
INDI::PropertyLight SafetyStatusLP {1};

// In initProperties()
SafetyStatusLP[0].fill("SAFETY", "Safety", IPS_IDLE);
SafetyStatusLP.fill(getDeviceName(), "SAFETY_STATUS", "Status", 
                    MAIN_CONTROL_TAB, IPS_IDLE);

2. Update the Status 

// When your safety condition changes
IPState safetyState = IPS_OK;  // or IPS_BUSY, IPS_ALERT

if (criticalCondition)
    safetyState = IPS_ALERT;
else if (warningCondition)
    safetyState = IPS_BUSY;
else
    safetyState = IPS_OK;

SafetyStatusLP.setState(safetyState);
SafetyStatusLP.apply();

3. Define/Delete with Connection 

// In updateProperties()
if (isConnected())
    defineProperty(SafetyStatusLP);
else
    deleteProperty(SafetyStatusLP);

Troubleshooting

Device Not Appearing in Status

Symptoms: Device listed in connection string but not appearing in SAFETY_STATUS

Possible Causes:

  1. Device name misspelled (case-sensitive)
  2. Device not connected on specified host
  3. Device doesn’t implement SAFETY_STATUS property
  4. Network connectivity issues

Solutions:

  • Verify device name matches exactly (check device.getDeviceName())
  • Ensure device is connected before Safety Monitor connects
  • Check device logs for SAFETY_STATUS property definition
  • Test network connectivity to remote hosts

Status Always Shows “Idle”

Symptoms: SAFETY_STATUS elements stuck at Idle

Possible Causes:

  1. Device offline
  2. Device hasn’t sent SAFETY_STATUS property yet
  3. Property not being updated by device

Solutions:

  • Check device connection status
  • Wait for device initialization
  • Enable debug logging to see property updates

Override Not Working

Symptoms: Override switch doesn’t force status to Ok

Possible Causes:

  1. Switch not properly saved
  2. Using individual element states instead of overall state

Solutions:

  • Ensure override switch is On (check switch state)
  • Monitor overall property state, not individual elements
  • Check driver logs for override confirmation

Best Practices

  1. Start Simple: Begin with one or two devices, add more as needed
  2. Test Thoroughly: Verify safety shutdown sequences before deployment
  3. Monitor Logs: Enable debug logging during initial setup
  4. Use Override Sparingly: Only for genuine emergencies
  5. Regular Checks: Periodically verify all monitored devices are online
  6. Document Configuration: Keep notes on which devices are monitored and why

See Also