Files
templates/python/protocan/balsam.py

99 lines
3.5 KiB
Python

"""Balsam 167 legacy CAN register decoder backed by the shared C99 core."""
from __future__ import annotations
from dataclasses import dataclass
from .native import NativeProtocolUnavailable, get_native_protocol
BASE_ID = 0x00BA0000
DATA_OFFSET = 0x10
NODE_COUNT = 13
@dataclass(frozen=True)
class BalsamRegister:
address: int
value: int
name: str
@property
def signed_value(self) -> int:
return self.value if self.value < 0x8000 else self.value - 0x10000
@dataclass(frozen=True)
class BalsamFrame:
can_id: int
device: int
device_name: str
from_device: bool
start_address: int
present_mask: int
registers: tuple[BalsamRegister, ...]
@property
def summary(self) -> str:
direction = "данные" if self.from_device else "команда"
values = ", ".join(
"%s=0x%04X (%d)" % (item.name or "R%04X" % item.address,
item.value, item.signed_value)
for item in self.registers
) or "нет отмеченных регистров"
return "BALZAM · %s · %s · %s" % (self.device_name, direction, values)
def is_balsam_id(can_id: int) -> bool:
relative = (can_id & 0x1FFFFFFF) - BASE_ID
return (0 <= relative < NODE_COUNT
or DATA_OFFSET <= relative < DATA_OFFSET + NODE_COUNT)
def decode(can_id: int, data: bytes, native=None) -> BalsamFrame | None:
"""Decode one abstract Balsam frame: BE mask/address plus three BE words."""
if native is None:
try:
native = get_native_protocol()
except NativeProtocolUnavailable:
return _decode_fallback(can_id, data)
status, decoded = native.balsam_decode(can_id, bytes(data))
if status == 0:
return None
if status == -2:
raise ValueError("BALZAM CAN frame must contain exactly 8 data bytes")
if status != 1 or decoded is None:
raise ValueError("invalid BALZAM CAN frame")
device, direction, mask, start, values = decoded
registers = tuple(
BalsamRegister(start + index, values[index],
native.balsam_register_name(device, start + index))
for index in range(3) if mask & (4 >> index)
)
return BalsamFrame(can_id & 0x1FFFFFFF, device,
native.balsam_device_name(device), direction == 1,
start, mask, registers)
def _decode_fallback(can_id: int, data: bytes) -> BalsamFrame | None:
if not is_balsam_id(can_id):
return None
if len(data) != 8:
raise ValueError("BALZAM CAN frame must contain exactly 8 data bytes")
relative = (can_id & 0x1FFFFFFF) - BASE_ID
device = (relative & 0x0F) + 1
header = int.from_bytes(data[:2], "big")
values = tuple(int.from_bytes(data[offset:offset + 2], "big")
for offset in (2, 4, 6))
names = {
1: "Трансформатор 1", 2: "Трансформатор 2",
3: "Силовой блок 1", 4: "Силовой блок 2", 5: "УМП 1", 6: "УМП 2",
7: "Двигатель", 8: "ВЭП", 9: "Задатчик", 13: "Терминал",
}
start, mask = header & 0x1FFF, (header >> 13) & 7
registers = tuple(BalsamRegister(start + i, values[i], "")
for i in range(3) if mask & (4 >> i))
return BalsamFrame(can_id & 0x1FFFFFFF, device,
names.get(device, "Узел %d" % device),
relative >= DATA_OFFSET, start, mask, registers)