node-red-contrib-deadband 1.0.1
Node-RED deadband filter - only passes values when change exceeds threshold
node-red-contrib-deadband
Node-RED Deadband filter - only forwards values when the change exceeds a threshold.
Features
- Filters small value changes (noise)
- Configurable deadband threshold
- Optional initial reference value
- Runtime override via msg
- Reset function
Behavior
- Change >= Deadband → value is forwarded + new reference stored
- Change < Deadband → message is blocked, no output
- First value always passes through (sets reference)
Example
Deadband = 0.5, reference = 20.0:
Input 20.3 → Δ0.3 → blocked
Input 20.6 → Δ0.6 → forwarded, new ref = 20.6
Input 20.8 → Δ0.2 → blocked
Input 21.2 → Δ0.6 → forwarded, new ref = 21.2
Configuration
| Property | Description | Default |
|---|---|---|
| Deadband | Minimum change to forward value | 0.5 |
| Initial Value | Initial reference value (optional) | - |
Input
msg.payload - Numeric value to filter
Runtime Overrides
| Property | Description |
|---|---|
msg.deadband |
Overrides deadband temporarily |
msg.reset |
true = reset reference value |
Output
{ "payload": 20.6 }
The original msg object is forwarded unchanged.
Use Cases
| Application | Deadband |
|---|---|
| Temperature sensor | 0.5 |
| Analog value (0-100) | 2 |
| Power consumption (Watt) | 50 |
Node Status
- Idle - Waiting for first input
- ✓ 20.6 - Value forwarded
- ✗ 20.3 (Δ0.3) - Value blocked
Author
sr.rpo
License
MIT