"""Modbus client async UDP communication.""" from __future__ import annotations import socket import time from collections.abc import Callable from pymodbus.client.base import ModbusBaseClient, ModbusBaseSyncClient from pymodbus.exceptions import ConnectionException from pymodbus.framer import FramerType from pymodbus.logging import Log from pymodbus.pdu import ModbusPDU from pymodbus.transport import CommParams, CommType DGRAM_TYPE = socket.SOCK_DGRAM class AsyncModbusUdpClient(ModbusBaseClient): """**AsyncModbusUdpClient**. Fixed parameters: :param host: Host IP address or host name Optional parameters: :param framer: Framer name, default FramerType.SOCKET :param port: Port used for communication. :param name: Set communication name, used in logging :param source_address: source address of client, :param reconnect_delay: Minimum delay in seconds.milliseconds before reconnecting. :param reconnect_delay_max: Maximum delay in seconds.milliseconds before reconnecting. :param timeout: Timeout for connecting and receiving data, in seconds. :param retries: Max number of retries per request. :param trace_packet: Called with bytestream received/to be sent :param trace_pdu: Called with PDU received/to be sent :param trace_connect: Called when connected/disconnected .. tip:: The trace methods allow to modify the datastream/pdu ! .. tip:: **reconnect_delay** doubles automatically with each unsuccessful connect, from **reconnect_delay** to **reconnect_delay_max**. Set `reconnect_delay=0` to avoid automatic reconnection. Example:: from pymodbus.client import AsyncModbusUdpClient async def run(): client = AsyncModbusUdpClient("localhost") await client.connect() ... client.close() Please refer to :ref:`Pymodbus internals` for advanced usage. """ def __init__( # pylint: disable=too-many-arguments self, host: str, *, framer: FramerType = FramerType.SOCKET, port: int = 502, name: str = "comm", source_address: tuple[str, int] | None = None, reconnect_delay: float = 0.1, reconnect_delay_max: float = 300, timeout: float = 3, retries: int = 3, trace_packet: Callable[[bool, bytes], bytes] | None = None, trace_pdu: Callable[[bool, ModbusPDU], ModbusPDU] | None = None, trace_connect: Callable[[bool], None] | None = None, ) -> None: """Initialize Asyncio Modbus UDP Client.""" self.comm_params = CommParams( comm_type=CommType.UDP, host=host, port=port, comm_name=name, source_address=source_address, reconnect_delay=reconnect_delay, reconnect_delay_max=reconnect_delay_max, timeout_connect=timeout, ) if framer not in [FramerType.SOCKET, FramerType.RTU, FramerType.ASCII]: raise TypeError("Only FramerType SOCKET/RTU/ASCII allowed.") ModbusBaseClient.__init__( self, framer, retries, self.comm_params, trace_packet, trace_pdu, trace_connect, ) self.source_address = source_address class ModbusUdpClient(ModbusBaseSyncClient): """**ModbusUdpClient**. Fixed parameters: :param host: Host IP address or host name Optional parameters: :param framer: Framer name, default FramerType.SOCKET :param port: Port used for communication. :param name: Set communication name, used in logging :param source_address: source address of client, :param reconnect_delay: Not used in the sync client :param reconnect_delay_max: Not used in the sync client :param timeout: Timeout for connecting and receiving data, in seconds. :param retries: Max number of retries per request. :param trace_packet: Called with bytestream received/to be sent :param trace_pdu: Called with PDU received/to be sent :param trace_connect: Called when connected/disconnected .. tip:: The trace methods allow to modify the datastream/pdu ! Example:: from pymodbus.client import ModbusUdpClient async def run(): client = ModbusUdpClient("localhost") client.connect() ... client.close() Please refer to :ref:`Pymodbus internals` for advanced usage. """ def __init__( # pylint: disable=too-many-arguments self, host: str, *, framer: FramerType = FramerType.SOCKET, port: int = 502, name: str = "comm", source_address: tuple[str, int] | None = None, reconnect_delay: float = 0.1, reconnect_delay_max: float = 300, timeout: float = 3, retries: int = 3, trace_packet: Callable[[bool, bytes], bytes] | None = None, trace_pdu: Callable[[bool, ModbusPDU], ModbusPDU] | None = None, trace_connect: Callable[[bool], None] | None = None, ) -> None: """Initialize Modbus UDP Client.""" if framer not in [FramerType.SOCKET, FramerType.RTU, FramerType.ASCII]: raise TypeError("Only FramerType SOCKET/RTU/ASCII allowed.") self.comm_params = CommParams( comm_type=CommType.UDP, host=host, port=port, comm_name=name, source_address=source_address, reconnect_delay=reconnect_delay, reconnect_delay_max=reconnect_delay_max, timeout_connect=timeout, ) super().__init__( framer, retries, self.comm_params, trace_packet, trace_pdu, trace_connect, ) self.socket: socket.socket | None = None @property def connected(self) -> bool: """Connect internal.""" return self.socket is not None def connect(self): """Connect to the modbus udp server. :meta private: """ if self.socket: return True try: self.socket = socket.socket(-1, socket.SOCK_DGRAM) self.socket.settimeout(self.comm_params.timeout_connect) except OSError as exc: Log.error("Unable to create udp socket {}", exc) self.close() return self.socket is not None def close(self): """Close the underlying socket connection. :meta private: """ self.socket = None def send(self, request: bytes, addr: tuple | None = None) -> int: """Send data on the underlying socket. :meta private: """ _ = addr if not self.socket: raise ConnectionException(str(self)) if request: return self.socket.sendto( request, (self.comm_params.host, self.comm_params.port) ) return 0 def recv(self, size: int | None) -> bytes: """Read data from the underlying descriptor. :meta private: """ if not self.socket: raise ConnectionException(str(self)) if size is None: size = 4096 data = self.socket.recvfrom(size)[0] self.last_frame_end = round(time.time(), 6) return data def is_socket_open(self): """Check if socket is open. :meta private: """ return True def __repr__(self): """Return string representation.""" return ( f"<{self.__class__.__name__} at {hex(id(self))} socket={self.socket}, " f"ipaddr={self.comm_params.host}, port={self.comm_params.port}, timeout={self.comm_params.timeout_connect}>" )