Low Threshold Condition

Low Threshold Condition: Under-Limit Detection

The Low Threshold Condition monitors data point values and triggers workflows when values fall below a specified threshold. This is crucial for detecting low-level conditions, resource depletion, and maintaining minimum operating parameters.

Info: This is a Trigger node type that can be used to trigger workflows based on data value conditions. When a monitored data point falls below the threshold, this trigger executes all of its child executor nodes.

Overview

Low Threshold triggers enable automated detection and response to under-limit conditions. They’re essential for maintaining minimum levels, detecting resource depletion, and ensuring systems don’t drop below safe operating parameters.

Key Features

• Continuous Monitoring: Always watching for values dropping below threshold
• Configurable Threshold: Set the exact minimum acceptable value
• Immediate Response: Instant execution when threshold is breached
• Universal Compatibility: Works with any numeric data point
• Visual Alerts: Clear indication when values are too low
• Flexible Actions: Trigger any combination of child executors

Threshold Monitoring Flow

graph TD
    A[Data Point Updates] --> B[Threshold Monitor Checks]
    B --> C{Value < Threshold?}
    C -->|No| D[Continue Monitoring]
    C -->|Yes| E[Set Trigger to EXECUTED]
    E --> F[Execute Child Executors]
    F --> G[Perform Actions]
    G --> H[Refill/Alert/Activate]
    H --> D

How It Works

The Low Threshold trigger provides continuous under-limit detection:

1. Configuration: Set minimum threshold value and link to data point
2. Monitoring: System continuously evaluates the data point’s value
3. Comparison: Each update checks if current value < threshold
4. Trigger: When condition is met, trigger transitions to EXECUTED state
5. Execution: All child executor nodes are activated
6. Response: Configured actions execute (refill, alert, activate backup)

Configuration

Field	Description	Required
threshold	Numeric value that triggers the alarm	Yes
dataPointId	ID of data point to monitor	Yes

Use Cases

• Low Water Level: Automatically refill tanks when level drops
• Battery Monitoring: Alert or activate charging at low battery
• Temperature Minimums: Activate heating when temperature drops
• Pressure Loss: Detect and respond to pressure drops
• Inventory Management: Alert when supplies run low
• Resource Depletion: Monitor consumable resources
• Performance Monitoring: Detect performance degradation

Example Workflows

Automatic Water Tank Refill:

1. Data Point: Water level sensor (updating continuously)
2. Trigger: Low Threshold (< 20% full)
3. Executor: Pin Control (open inlet valve)
4. Executor: Lambda (log refill event)
5. Result: Tank automatically refills when low

Low Battery Alert:

1. Data Point: Battery voltage monitor
2. Trigger: Low Threshold (< 11.5V)
3. Executor: OutgoingWebHook (send low battery alert)
4. Executor: Pin Control (activate battery charger)

Freeze Protection:

1. Data Point: Temperature sensor
2. Trigger: Low Threshold (< 5°C)
3. Executor: Logic Gate (check other conditions)
4. Executor: Pin Control (activate heater)
5. Executor: OutgoingWebHook (notify operator)

Pressure Loss Detection:

1. Data Point: Pressure sensor
2. Trigger: Low Threshold (< 30 PSI)
3. Executor: Lambda (diagnostic check)
4. Executor: OutgoingWebHook (maintenance alert)
5. Executor: Pin Control (activate backup pump)

Advanced Patterns

Hysteresis Control: Combine Low and High thresholds to prevent oscillation:

• Low Threshold (< 20%): Start refilling
• High Threshold (> 80%): Stop refilling

graph TD
    A[Level Monitor] --> B{Level < 20%?}
    B -->|Yes| C[Start Refill]
    C --> D{Level > 80%?}
    D -->|Yes| E[Stop Refill]
    D -->|No| C
    B -->|No| F{Level > 80%?}
    F -->|Yes| E
    F -->|No| A

Multi-Stage Alerts: Create escalating responses:

• Low Threshold 1 (< 40%): Warning notification
• Low Threshold 2 (< 20%): Email alert + activate backup
• Low Threshold 3 (< 10%): Emergency shutdown

Intelligent Resource Management:

Low Level AND Business Hours → Order Supplies
Low Level AND After Hours → Send Alert Only

Integration Points

• Data Points: Monitor any numeric measurement
• Executors: Trigger automated responses
• Pins: Control refill valves, pumps, heaters
• Logic Gates: Add conditional logic to responses
• MQTT: Publish low-level events to message systems
• OutgoingWebHook: Send alerts to external systems

Best Practices

• Safety Margins: Set thresholds well above critical minimums
• Hysteresis: Use both low and high thresholds to prevent rapid cycling
• Response Validation: Verify corrective actions are working
• Backup Systems: Have redundant sensors for critical applications
• Logging: Always log threshold events for trend analysis
• Testing: Regularly test threshold triggers and responses
• Gradual Action: Consider gradual responses rather than full activation

Common Applications

Application	Threshold	Action
Water Tank	< 20%	Open inlet valve
Battery	< 12V	Activate charger
Temperature	< 10°C	Enable heater
Pressure	< 40 PSI	Start backup pump
Inventory	< 100 units	Order supplies
Fuel Level	< 25%	Refuel alert

Comparison with High Threshold

Feature	Low Threshold	High Threshold
Trigger Condition	Value < Threshold	Value > Threshold
Common Use	Under-limit detection	Over-limit detection
Example	Low battery warning	Overheat alarm
Typical Action	Refill/Recharge/Activate	Shutdown/Relief/Alert

Low Threshold Conditions are fundamental for maintaining system resources, preventing shortages, and ensuring continuous operation of automated systems.