Overview
This node allows writing data to MODBUS devices by specifying a memory address (register index), unit ID, data type, and the value to write. It is useful for controlling or configuring MODBUS-compatible devices such as industrial controllers, sensors, or actuators by sending specific values to their registers. For example, it can be used to set a temperature setpoint on a thermostat or change the state of a relay.
Use Case Examples
- Writing a signed 16-bit integer value to a specific register to control a device parameter.
- Sending an unsigned 32-bit integer to update a device configuration behind a MODBUS bridge using a unit ID.
Properties
| Name | Meaning |
|---|---|
| Memory Address | The memory address (register index) to write to. |
| Unit-ID | Unit-ID to address devices behind MODBUS bridges. |
| Data Type | The data type of the value to write, determining how the value is encoded (e.g., signed 16-bit integer, unsigned 32-bit integer). |
| Value | The numeric value to write to the specified memory address, constrained by the selected data type's range. |
Output
JSON
data- Response data from the MODBUS device after writing the value to the specified memory address.
Dependencies
- Requires a MODBUS API credential for authentication and connection to the MODBUS device.
Troubleshooting
- Value out of range errors if the provided value does not fit into the selected data type's limits. Ensure the value is within the allowed range for the chosen data type.
- MODBUS communication errors if the device is unreachable or the unit ID is incorrect. Verify network connectivity and correct unit ID configuration.
- Errors indicating unsupported data types if a data type other than the supported ones is selected. Use only the implemented data types: int16, int32, uint16, uint32.