digitalpetri Modbus documentation

digitalpetri Modbus provides Java 17 client and server APIs for Modbus TCP, Modbus TCP Security, Modbus RTU over serial, and Modbus RTU over TCP. Choose a how-to guide to build or operate an integration, a concept page for the underlying model, or a reference page for exact library behavior.

New to this library? Read in this order: the Modbus mental model, then Installation and modules, then Read and write over Modbus TCP. To try the client without device hardware, run the local server from Expose data over Modbus TCP first and point the client example at it.

How-to guides

Clients

• Read and write over Modbus TCP
• Communicate over serial RTU
• Secure a Modbus TCP client with TLS

Servers

• Expose data over Modbus TCP

Operations

• Configure timeouts and reconnection
• Troubleshoot communication

Concepts

• A Modbus mental model
• Addressing, unit IDs, and data
• Transports, framing, and security

Reference

• Installation and modules
• Feature and transport matrix
• Client and server behavior
• Transport configuration
• Function codes and PDUs
• Errors and exceptions
• Lifecycle, concurrency, and resources
• API reference

See Installation and modules for published versions and Maven coordinates.