Modbus Set Coils
ModbusSetCoilsAction sets multiple coil values on a direct ModbusThing using a compact pattern. Use it for relay presets, digital outputs, safe partial updates, and event-driven hardware changes.
Apply a coil pattern to a direct Modbus device
The action updates the ModbusThing writable coil buffer. The device write loop sends changes when the buffered value differs from the last read device state.
Set true
Use 1 to turn a coil on.
Set false
Use 0 to turn a coil off.
No change
Use x for coils that must not be touched.
Relay and output presets
Relay board control
Switch lamps, sirens, locks, controller inputs, or enable lines from rules or manual actions.
Safe partial update
Pattern 1x0x sets coil 0 on, leaves coil 1 unchanged, sets coil 2 off, and leaves coil 3 unchanged.
Event-driven output
Attach the action to Event Manager rules when detection, QR, sound, or custom events should change hardware outputs.
Configuration parameters
| Parameter | Required | Description | Default |
|---|---|---|---|
Title | Yes | Display name of the action. | None |
Modbus | Yes | Target direct ModbusThing. | None |
Coils values | Yes | Pattern matching ^[01x]+$: 1 on, 0 off, x unchanged. | None |
Operational notes
Use explicit patterns
A one-character value affects only the first coil. Use the full pattern when the intent is multi-output control.
Actuator safety
Treat coil writes as actuator commands and test patterns before controlling motors, pumps, heaters, locks, or safety outputs.