5.3.1.17.4.1. cli.com.modbus_com.Modbus

class cli.com.modbus_com.Modbus(name: str, parameter: ModbusParameter)

Bases: ComInterface

High-level adapter for Modbus process-based communication.

This class manages the lifecycle of a ModbusProcess and provides queue-based read/write methods for commands and results.

read(block: bool = False, timeout: float | None = None) → dict | None

Read a result dictionary from the output queue.

Parameters:

• block (bool) – Whether to block until a result is available.

• timeout (float | None) – Optional timeout (seconds) when blocking.

Returns:

A command/result dictionary (including ‘values’) if available, otherwise None.

Return type:

dict | None

Notes

Returns None if the process is not alive and the output queue is empty, to avoid blocking forever.

write(command: dict) → None

Send a Modbus command to the input queue for execution.

Parameters:

command (dict) – The Modbus command as a dictionary. Expected keys: ‘date’, ‘code’, ‘address’, ‘length’, ‘values’.

Raises:

RuntimeError – If the Modbus process is not running.