Files
tsun-gen3-proxy/app/src/modbus.py

218 lines
9.0 KiB
Python

import struct
import logging
import asyncio
from typing import Generator
if __name__ == "app.src.modbus":
from app.src.infos import Register
else: # pragma: no cover
from infos import Register
#######
# TSUN uses the Modbus in the RTU transmission mode.
# see: https://modbus.org/docs/Modbus_over_serial_line_V1_02.pdf
#
# A Modbus PDU consists of: 'Function-Code' + 'Data'
# A Modbus RTU message consists of: 'Addr' + 'Modbus-PDU' + 'CRC-16'
#
# The 16-bit CRC is known as CRC-16-ANSI(reverse)
# see: https://en.wikipedia.org/wiki/Computation_of_cyclic_redundancy_checks
#######
CRC_POLY = 0xA001 # (LSBF/reverse)
CRC_INIT = 0xFFFF
class Modbus():
INV_ADDR = 1
READ_REGS = 3
READ_INPUTS = 4
WRITE_SINGLE_REG = 6
'''Modbus function codes'''
__crc_tab = []
map = {
0x2007: {'reg': Register.MAX_DESIGNED_POWER, 'fmt': '!H', 'ratio': 1}, # noqa: E501
# 0x????: {'reg': Register.INVERTER_STATUS, 'fmt': '!H'}, # noqa: E501
0x3008: {'reg': Register.VERSION, 'fmt': '!H', 'eval': "f'V{(result>>12)}.{(result>>8)&0xf}.{(result>>4)&0xf}{result&0xf}'"}, # noqa: E501
0x3009: {'reg': Register.GRID_VOLTAGE, 'fmt': '!H', 'ratio': 0.1}, # noqa: E501
0x300a: {'reg': Register.GRID_CURRENT, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x300b: {'reg': Register.GRID_FREQUENCY, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x300c: {'reg': Register.INVERTER_TEMP, 'fmt': '!H', 'eval': 'result-40'}, # noqa: E501
# 0x300d
0x300e: {'reg': Register.RATED_POWER, 'fmt': '!H', 'ratio': 1}, # noqa: E501
0x300f: {'reg': Register.OUTPUT_POWER, 'fmt': '!H', 'ratio': 0.1}, # noqa: E501
0x3010: {'reg': Register.PV1_VOLTAGE, 'fmt': '!H', 'ratio': 0.1}, # noqa: E501
0x3011: {'reg': Register.PV1_CURRENT, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x3012: {'reg': Register.PV1_POWER, 'fmt': '!H', 'ratio': 0.1}, # noqa: E501
0x3013: {'reg': Register.PV2_VOLTAGE, 'fmt': '!H', 'ratio': 0.1}, # noqa: E501
0x3014: {'reg': Register.PV2_CURRENT, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x3015: {'reg': Register.PV2_POWER, 'fmt': '!H', 'ratio': 0.1}, # noqa: E501
0x3016: {'reg': Register.PV3_VOLTAGE, 'fmt': '!H', 'ratio': 0.1}, # noqa: E501
0x3017: {'reg': Register.PV3_CURRENT, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x3018: {'reg': Register.PV3_POWER, 'fmt': '!H', 'ratio': 0.1}, # noqa: E501
0x3019: {'reg': Register.PV4_VOLTAGE, 'fmt': '!H', 'ratio': 0.1}, # noqa: E501
0x301a: {'reg': Register.PV4_CURRENT, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x301b: {'reg': Register.PV4_POWER, 'fmt': '!H', 'ratio': 0.1}, # noqa: E501
0x301c: {'reg': Register.DAILY_GENERATION, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x301d: {'reg': Register.TOTAL_GENERATION, 'fmt': '!L', 'ratio': 0.01}, # noqa: E501
0x301f: {'reg': Register.PV1_DAILY_GENERATION, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x3020: {'reg': Register.PV1_TOTAL_GENERATION, 'fmt': '!L', 'ratio': 0.01}, # noqa: E501
0x3022: {'reg': Register.PV2_DAILY_GENERATION, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x3023: {'reg': Register.PV2_TOTAL_GENERATION, 'fmt': '!L', 'ratio': 0.01}, # noqa: E501
0x3025: {'reg': Register.PV3_DAILY_GENERATION, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x3026: {'reg': Register.PV3_TOTAL_GENERATION, 'fmt': '!L', 'ratio': 0.01}, # noqa: E501
0x3028: {'reg': Register.PV4_DAILY_GENERATION, 'fmt': '!H', 'ratio': 0.01}, # noqa: E501
0x3029: {'reg': Register.PV4_TOTAL_GENERATION, 'fmt': '!L', 'ratio': 0.01}, # noqa: E501
}
def __init__(self, snd_handler, timeout: int = 1):
if not len(self.__crc_tab):
self.__build_crc_tab(CRC_POLY)
self.que = asyncio.Queue(100)
self.snd_handler = snd_handler
self.timeout = timeout
self.last_addr = 0
self.last_fcode = 0
self.last_len = 0
self.last_reg = 0
self.err = 0
self.loop = asyncio.get_event_loop()
self.req_pend = False
self.tim = None
def start_timer(self):
if self.req_pend:
return
self.req_pend = True
self.tim = self.loop.call_later(self.timeout, self.timeout_cb)
# logging.debug(f'Modbus start timer {self}')
def stop_timer(self):
self.req_pend = False
# logging.debug(f'Modbus stop timer {self}')
if self.tim:
self.tim.cancel()
self.get_next_req()
def timeout_cb(self):
self.req_pend = False
logging.info(f'Modbus timeout {self}')
self.get_next_req()
def get_next_req(self) -> None:
if self.req_pend:
return
try:
item = self.que.get_nowait()
req = item['req']
self.rsp_handler = item['rsp_hdl']
self.last_addr = req[0]
self.last_fcode = req[1]
res = struct.unpack_from('>HH', req, 2)
self.last_reg = res[0]
self.last_len = res[1]
self.start_timer()
self.snd_handler(req)
except asyncio.QueueEmpty:
pass
def build_msg(self, addr, func, reg, val) -> None:
msg = struct.pack('>BBHH', addr, func, reg, val)
msg += struct.pack('<H', self.__calc_crc(msg))
self.que.put_nowait({'req': msg,
'rsp_hdl': None})
if self.que.qsize() == 1:
self.get_next_req()
def recv_req(self, buf: bytearray, rsp_handler=None) -> bool:
# logging.info(f'recv_req: first byte modbus:{buf[0]} len:{len(buf)}')
if not self.check_crc(buf):
self.err = 1
logging.error('Modbus recv: CRC error')
return False
self.que.put_nowait({'req': buf,
'rsp_hdl': rsp_handler})
if self.que.qsize() == 1:
self.get_next_req()
return True
def recv_resp(self, info_db, buf: bytearray, node_id: str) -> \
Generator[tuple[str, bool], None, None]:
# logging.info(f'recv_resp: first byte modbus:{buf[0]} len:{len(buf)}')
if not self.req_pend:
self.err = 5
return
if not self.check_crc(buf):
logging.error('Modbus resp: CRC error')
self.err = 1
return
if buf[0] != self.last_addr:
logging.info(f'Modbus resp: Wrong addr {buf[0]}')
self.err = 2
return
fcode = buf[1]
if fcode != self.last_fcode:
logging.info(f'Modbus: Wrong fcode {fcode} != {self.last_fcode}')
self.err = 3
return
if self.last_addr == self.INV_ADDR and \
(fcode == 3 or fcode == 4):
elmlen = buf[2] >> 1
if elmlen != self.last_len:
logging.info(f'Modbus: len error {elmlen} != {self.last_len}')
self.err = 4
return
first_reg = self.last_reg # save last_reg before sending next pdu
self.stop_timer() # stop timer and send next pdu
for i in range(0, elmlen):
addr = first_reg+i
if addr in self.map:
row = self.map[addr]
info_id = row['reg']
fmt = row['fmt']
val = struct.unpack_from(fmt, buf, 3+2*i)
result = val[0]
if 'eval' in row:
result = eval(row['eval'])
if 'ratio' in row:
result = round(result * row['ratio'], 2)
keys, level, unit, must_incr = info_db._key_obj(info_id)
if keys:
name, update = info_db.update_db(keys, must_incr,
result)
yield keys[0], update, result
if update:
info_db.tracer.log(level,
f'[\'{node_id}\']MODBUS: {name}'
f' : {result}{unit}')
else:
self.stop_timer()
def check_crc(self, msg) -> bool:
return 0 == self.__calc_crc(msg)
def __calc_crc(self, buffer: bytes) -> int:
crc = CRC_INIT
for cur in buffer:
crc = (crc >> 8) ^ self.__crc_tab[(crc ^ cur) & 0xFF]
return crc
def __build_crc_tab(self, poly) -> None:
for index in range(256):
data = index << 1
crc = 0
for _ in range(8, 0, -1):
data >>= 1
if (data ^ crc) & 1:
crc = (crc >> 1) ^ poly
else:
crc >>= 1
self.__crc_tab.append(crc)