118 lines
4.2 KiB
Python

from pymodbus.client.sync import ModbusSerialClient
from pymodbus.pdu import ExceptionResponse
from pymodbus.exceptions import ModbusIOException
import RS485Ext
import struct
import time
def registersToIeeeFloat(i):
return struct.unpack('f', bytes(
[((x & 0xff00) >> 8) if y else (x & 0x00ff)
for x in i[::-1]
for y in [False, True]
]
)
)[0]
def registersToIeeeFloatReverse(i):
return struct.unpack('f', bytes(
[((x & 0xff00) >> 8) if y else (x & 0x00ff)
for x in i
for y in [False, True]
]
)
)[0]
def dataConverter(t, d):
if t == 'F':
return registersToIeeeFloat(d)
elif t == 'RF':
return registersToIeeeFloatReverse(d)
else:
raise Exception("Converter '{0}' is not supported".format(t))
class ModbusException(Exception):
def __init__(self, resp):
self.msg = str(result)
def __str__(self):
return self.msg
class ModbusRequestDefinition(object):
def __init__(self, kind, unit, address, count, converter, label):
self.kind = kind
self.unit = unit
self.address = address
self.count = count
self.converter = converter
self.label = label
reqs = [
# ModbusRequestDefinition(4, 0x2000, 2, 'F', '(ERR) Unavailable device'),
# ModbusRequestDefinition(1, 0x2000, 4, 'F', '(ERR) Wrong register size'),
# ModbusRequestDefinition(1, 0x2000, 2, 'F', 'Voltage'),
# ModbusRequestDefinition(1, 0x2020, 2, 'F', 'Frequency'),
# ModbusRequestDefinition(1, 0x2060, 2, 'F', 'Current'),
# ModbusRequestDefinition('H', 3, 0x0004, 2, 'RF', 'Resistance Channel 1'),
# ModbusRequestDefinition('H', 3, 0x000C, 2, 'RF', 'Temperature Channel 1'),
# ModbusRequestDefinition('H', 3, 0x0014, 2, 'RF', 'Resistance Channel 2'),
# ModbusRequestDefinition('H', 3, 0x001C, 2, 'RF', 'Temperature Channel 2'),
ModbusRequestDefinition('D', 4, 0x0000, 1, '', 'Discrete Input'),
ModbusRequestDefinition('I', 5, 0x0001, 1, '', 'Temperature'),
ModbusRequestDefinition('I', 5, 0x0002, 1, '', 'Humidity'),
]
def getSerial():
return RS485Ext.RS485Ext(port='/dev/ttyAMA0', baudrate=9600, stopbits=1,
timeout=1)
client = ModbusSerialClient(method='rtu')
client.socket = getSerial()
client.connect()
delay = 0.05
period = 0.5
while True:
for req in reqs:
try:
time.sleep(delay)
if req.kind == 'H':
# print("Trying to read: {0} {1} {2}".format(req.address, req.count, req.unit))
result = client.read_holding_registers(address=req.address,
count=req.count,
unit=req.unit)
if type(result) in [ExceptionResponse, ModbusIOException]:
raise ModbusException(result)
print("{0}: {1:.2f}".format(req.label,
dataConverter(req.converter,
result.registers)))
elif req.kind == 'D':
result = client.read_discrete_inputs(address=req.address,
count=req.count,
unit=req.unit)
if type(result) in [ExceptionResponse, ModbusIOException]:
raise ModbusException(result)
print("{0}: {1!s}".format(req.label, result.bits))
elif req.kind == 'I':
result = client.read_input_registers(address=req.address,
count=req.count,
unit=req.unit)
if type(result) in [ExceptionResponse, ModbusIOException]:
raise ModbusException(result)
print("{0}: {1}".format(req.label, result.registers))
except ModbusException as e:
print("ERROR when querying '{0}': {1!s}".format(req.label, e))
if client.socket is None:
print("renew socket")
client.socket = getSerial()
print("-------------")
time.sleep(period)
client.close()