3.9.0

Connection parameters

This release introduces backend-neutral, frozen connection parameter objects:

• ModbusTcpParams
• ModbusUdpParams
• ModbusTlsParams
• ModbusSerialParams

The recommended pattern for new code is to create one of these parameter objects and pass it to the canonical ModbusConnection class for the selected backend:

from modbus_connection import ModbusTcpParams
from modbus_connection.pymodbus import ModbusConnection

connection = ModbusConnection(
    ModbusTcpParams(host="192.168.1.50", port=502)
)
await connection.connect()

Keeping the connection details in a reusable object prepares the API for upcoming lazy-loading and auto-reconnect behavior, where a connection can retain everything it needs to establish the link when needed.

The existing connect_tcp, connect_udp, connect_tls, and connect_serial factories are not deprecated and remain supported. This release promotes the params-first connection constructors as the preferred API for new code. The existing PymodbusConnection and TmodbusConnection names also remain available as backward-compatible aliases.

What's Changed

• Make ModbusConnection a params-carrying base class that establishes its own link by @balloob in #61
• Add the Open Home Foundation AI Policy by @frenck in #64
• Format documentation Python snippets with Ruff by @balloob in #65
• Add SSL context to TLS params by @balloob in #66
• Select CLI backend per connection by @balloob in #67
• Recommend params-first connection construction by @balloob in #68
• Make backend ModbusConnection names canonical by @balloob in #70
• Validate framer names in connection params by @balloob in #69

Full Changelog: 3.8.1...3.9.0