def __new__(cls, addr, *args, **kwargs):
""" Overridden __new__ for setting the size. """
return ModbusRegister.__new__(cls, addr, size=3, *args, **kwargs)
def __new__(cls, addr, *args, **kwargs):
""" Overridden __new__ for setting the signed option. """
return ModbusRegister.__new__(cls, addr, signed=True, *args, **kwargs)
def __new__(cls, addr, *args, **kwargs):
""" Overridden __new__ for fixing the register size and
forcing unsigned values since 2's complement is used here.
"""
return ModbusRegister.__new__(cls, addr, size=2, signed=False, *args, **kwargs)
def __new__(cls, addr, *args, **kwargs):
""" Overridden __new__ for fixing the register size. """
return ModbusRegister.__new__(cls, addr, *args, **kwargs)
class DigiRail_2A(RTUModbusHWDevice):
""" DigiRail-2A A/D converter HW device
The supported model is the RTU RS485 one, the RS485 bus being connected
via a USB.RS485 interface.
"""
DEFAULT_BAUDRATE = 19200
# registers
# - configuration
REG_MODBUS_ADDR = ModbusRegister(3)
REG_INPUT_TYPE_1 = ModbusRegister(21)
REG_INPUT_TYPE_2 = ModbusRegister(22)
REG_MEAS_UNIT_1 = ModbusRegister(26)
REG_MEAS_UNIT_2 = ModbusRegister(27)
# - data
REG_PV_ENG_1 = ModbusRegister(14)
REG_PV_ENG_2 = ModbusRegister(15)
#: the compiled sequence of collected registers
COLLECTED_REGS = [REG_PV_ENG_1, REG_PV_ENG_2]
_TOTAL_INPUT_SIZE = reduce(lambda accum, size: accum + size,
[r.size for r in COLLECTED_REGS])
# Definition of the type of the poll() method result
# VERY IMPORTANT :
# The name of its items MUST match the name of the outputs described
# in the metadata stored in devcfg.d directory, since the notification
# events generation process is based on this.
# (see pycstbox.hyal.device.PolledDevice.poll() method for details)
OutputValues = namedtuple(
'OutputValues',
[
'in1', # input 1
'in2', # input 2
])
def __init__(self, port, unit_id):
"""
:param str port: serial port on which the RS485 interface is connected
:param int unit_id: the address of the device
"""
super(DigiRail_2A, self).__init__(port=port,
unit_id=int(unit_id),
logname='dr2a')
self._logger.info('reading inputs configuration from device...')
input_types = self.unpack_registers(
start_register=self.REG_INPUT_TYPE_1,
reg_count=2,
unpack_format='>hh')
input_units = self.unpack_registers(
start_register=self.REG_MEAS_UNIT_1,
reg_count=2,
unpack_format='>hh')
self._logger.info('creating corresponding model instances...')
self.inputs = [
DRInput(input_type, input_unit)
for input_type, input_unit in zip(input_types, input_units)
]
for n, input in enumerate(self.inputs):
self._logger.info('... [%d] %s', n + 1, input)
@property
def unit_id(self):
""" The id of the device """
return self.address
def poll(self):
""" Reads the registers data and returns the
values as a named tuple.
"""
# since the input registers are contiguous, optimise the operation by reading them in a single request
return self.OutputValues(**dict(
zip(self.OutputValues._fields, [
inp.physical_value(rv) for inp, rv in zip(
self.inputs,
self.unpack_registers(
self.REG_PV_ENG_1, reg_count=2, unpack_format=">hh"))
])))
def input_unit(self, channel_num):
try:
return self.inputs[channel_num - 1].unit
except KeyError:
raise ValueError('invalid channel number (%s)' % channel_num)
def is_enabled(self, channel_num):
try:
return self.inputs[channel_num - 1].enabled
except KeyError:
raise ValueError('invalid channel number (%s)' % channel_num)
