Overview
This node interacts with MODBUS devices to read data from specified memory addresses (registers). It supports reading various data types such as signed and unsigned integers of 16, 32, and 64 bits. The node is useful in industrial automation, monitoring, and control systems where MODBUS protocol is used to communicate with devices like sensors, meters, and controllers. For example, it can read temperature or pressure values from a sensor connected via MODBUS.
Use Case Examples
- Reading a signed 16-bit integer value from memory address 10 of a MODBUS device with Unit-ID 1.
- Reading multiple unsigned 32-bit integer values starting from memory address 20 to monitor several registers at once.
Properties
| Name | Meaning |
|---|---|
| Memory Address | The memory address (register index) to read from. |
| Unit-ID | Unit-ID to address devices behind modbus-bridges. |
| Data Type | The data type of the values to read from the memory address, such as signed or unsigned integers of various bit lengths. |
| Quantity | The number of data values to read from the memory address. |
Output
JSON
data- The data read from the MODBUS device, decoded according to the selected data type.
Dependencies
- MODBUS API credentials required for authentication and connection to the MODBUS device.
Troubleshooting
- Errors may occur if the value to write does not fit into the selected data type (for write operation).
- MODBUS communication errors may occur, indicated by error messages prefixed with 'MODBUS Error:'.
- No data received from the MODBUS device may cause an error.
- Ensure the correct Unit-ID and memory address are specified to avoid addressing errors.