Dane Sabo
3299181c70
M lazy-lock.json M lua/custom/configs/lspconfig.lua M lua/custom/init.lua A lua/custom/journal.lua A nvim_venv/bin/Activate.ps1 A nvim_venv/bin/activate A nvim_venv/bin/activate.csh A nvim_venv/bin/activate.fish
47 lines
1.4 KiB
Python
47 lines
1.4 KiB
Python
"""Modbus Socket frame implementation."""
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from __future__ import annotations
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from pymodbus.framer.base import FramerBase
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from pymodbus.logging import Log
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class FramerSocket(FramerBase):
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"""Modbus Socket frame type.
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Layout::
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[ MBAP Header ] [ Function Code] [ Data ]
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[ tid ][ pid ][ length ][ uid ]
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2b 2b 2b 1b 1b Nb
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length = uid + function code + data
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"""
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MIN_SIZE = 8
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def decode(self, data: bytes) -> tuple[int, int, int, bytes]:
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"""Decode ADU."""
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if (data_len := len(data)) < self.MIN_SIZE:
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Log.debug("Very short frame (NO MBAP): {} wait for more data", data, ":hex")
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return 0, 0, 0, self.EMPTY
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tid = int.from_bytes(data[0:2], 'big')
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msg_len = int.from_bytes(data[4:6], 'big') + 6
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dev_id = int(data[6])
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if data_len < msg_len:
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Log.debug("Short frame: {} wait for more data", data, ":hex")
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return 0, 0, 0, self.EMPTY
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if msg_len == 8 and data_len == 9:
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msg_len = 9
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return msg_len, dev_id, tid, data[7:msg_len]
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def encode(self, pdu: bytes, device_id: int, tid: int) -> bytes:
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"""Encode ADU."""
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frame = (
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tid.to_bytes(2, 'big') +
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b'\x00\x00' +
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(len(pdu) + 1).to_bytes(2, 'big') +
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device_id.to_bytes(1, 'big') +
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pdu
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)
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return frame
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