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Modbus Line Set Register

ModbusLineSetRegisterAction writes one holding register value to one slave device managed by a ModbusLineThing. Use it for PLC setpoints, controller parameters, analog outputs, modes, thresholds, timers, and corrective commands.

Write one holding register on a selected slave

The action performs a direct single holding-register write to the configured register address on the configured slave ID. The register must accept writes, and the device must be online.

PLC

Setpoints

Write speed, temperature, threshold, timer, mode, or analog output values.

BUS

Multi-slave automation

Target one controller among several devices on the same Modbus line.

FIX

Corrective command

Return equipment to a known value after an event, alarm, or operator action.

Configuration parameters

ParameterRequiredDescriptionDefault
Title
YesDisplay name of the action.None
Modbus line
YesTarget ModbusLineThing.None
Device
YesSlave device ID inside the selected line.None
Address
YesRaw holding-register address to write.None
Value
YesInteger value sent to the register. UI range is 0-32767.None

Operational notes

MAP

Use the configured register map

The dropdown is based on the holding-register map. Rename registers so action configuration remains understandable.

SCALE

Convert engineering values first

If the device expects signed values, scaled units, bit masks, or multi-register values, convert them before configuring the action.

ONL

Device must accept writes

The device must be online and the target register must support holding-register writes.

Related Modbus pages

Related tasks and pages