Modbus
The Modbus North Connector enables OIBus to write data to Modbus-compatible devices, allowing seamless integration with PLCs, RTUs, and other industrial equipment that supports the Modbus protocol.
Example Use Cases
- Process Control: Write setpoints and control values to PLCs
- Configuration Management: Update device parameters remotely
- System Integration: Bridge OIBus data with Modbus-compatible equipment
Specific Settings
Connection Configuration
| Setting | Description | Example Value |
|---|---|---|
| Host | IP address or hostname of the Modbus server machine. | 192.168.1.100 |
| Port | Port to use for connection (502 by default). | 502 |
| Connection timeout | Maximum time to wait for a connection (in milliseconds). | 10000 |
| Retry interval | Time to wait (in milliseconds) before reconnecting, whether after a connection failure or after a write command fails. | 10000 |
| Slave ID | Identifies the Modbus source machine (default is 1). | 1 |
| Address offset | For most PLCs, there is no offset (Modbus option). Some PLCs may start the address range at 1 instead of 0 (JBus option) | Modbus |
Data Format Options
| Setting | Description | Example Value |
|---|---|---|
| Endianness | Type of bit encoding. | Big endian |
| Swap Bytes | Whether bytes within a 16-bit word should be swapped. | Enabled/Disabled |
| Swap Words | Whether 16-bit words should be swapped within a 32-bit group. | Enabled/Disabled |
Use the tester below to preview how different endianness and swap settings affect the byte layout of a value written to a Modbus register:
Presets
This connector only writes single 16-bit registers or coils (writeSingleCoil / writeSingleRegister) — it has no
multi-register write path, so Endianness, Swap Bytes, and Swap Words are not currently applied when
sending data. Changing them has no effect on what gets written. The tester above illustrates the byte-layout concept
(shared with the Modbus South connector, where these settings are applied when reading), not this connector's
actual behavior.