我是python cffi的新手。我必须使用其索引或其通道名称来访问我的温度模块。正如你在QmixTC课上看到的那样，我正在尝试这两种方法。我收到了属性错误。在其他课程中，没有错误。有人可以帮我理解问题所在。我正在处理我的代码以及错误跟踪。谢谢。
main code with name qmix.py (importing it in to sample code):
class QmixTC (object):
"""
"""
def __init__(self, index=0, handle=None,name=''):
self.dll_dir = DLL_DIR
self.dll_file = os.path.join(self.dll_dir,
'labbCAN_Controller_API.dll')
self._ffi = FFI()
self._ffi.cdef(CONTROLLER_HEADER)
self._dll = self._ffi.dlopen(self.dll_file)
self._handle = self._ffi.new('dev_hdl *', 0)
if handle is None:
self.index = index
self._handle = self._ffi.new('dev_hdl *', 0)
self._call('LCC_GetChannelHandle', self.index, self._handle)
else:
self.index = None
self._handle = handle
self._ch_name="QmixTC_1_DO0_INA"
self._channel = self._ch_name + str(index)
self._call('LCC_LookupChanByName',
bytes(self._channel,'utf8'),
self._handle)
self.name = name
def _call(self, func_name, *args):
func = getattr(self._dll, func_name)
r = func(*args)
r = CHK(r, func_name, *args)
return r
def Setpoint_write (self, setpoint):
"""
Write setpoint value to controller device.
Parameters
[in] ChanHdl Valid handle of open controller channel
[in] fSetPointValue The setpoint value to write
Returns
Error code - ERR_NOERR indicates success
"""
self._call('LCC_WriteSetPoint', self._handle[0], setpoint)
def enable_controllLoop (self, enable):
"""
Enables / disables a control loop.
If the control loop is enabled, then the output value is calculated periodically.
Parameters
ChanHdl Valid handle of a controller channel
Enable 1 = enable, 0 = disable
Returns
Error code - ERR_NOERR indicates success
"""
self._call('LCC_EnableControlLoop', self._handle[0], enable)
def read_temp_value (self, actualvalue):
"""
Read actual value from device.
Parameters
[in] ChanHdl Valid handle of open controller channel
[out] pfActualValue Returns the actual controller value
Returns
Error code - ERR_NOERR indicates success
"""
self._call('LCC_ReadActualValue', self._handle[0], actualvalue)
if __name__ == '__main__':
import os.path as op
dll_dir = op.normpath('C:\\Users\\Ravikumar\\AppData\\Local\\QmixSDK')
config_dir = op.normpath('C:\\Users\\Public\\Documents\\QmixElements\\Projects\\QmixTC_Pump\\Configurations\\QmixTC_pump')
bus = QmixBus(config_dir=config_dir)
bus.open()
bus.start()
controller_0 = QmixTC(index=0)
controller_0.enable_controllLoop(1)
示例程序：
from __future__ import division, print_function
from win32api import GetSystemMetrics
import numpy as np
import os
import qmix
import pandas as pd
#%% CHANNEL INITIALIZATION
if __name__ == '__main__':
dll_dir = ('C:\\Users\\Ravikumar\\AppData\\Local\\QmixSDK')
config_dir = ('C:\\Users\\Public\\Documents\\QmixElements\\Projects\\QmixTC_test1\\Configurations\\QmixTC_test1')
qmix_bus = qmix.QmixBus(config_dir=config_dir,dll_dir=dll_dir)
qmix_bus.open()
qmix_bus.start()
controller_0 = qmix.QmixTC(index=0)
controller_0.Setpoint_write(50)
错误： 回溯（最近一次调用最后一次）：
File "<ipython-input-5-40d4a3db9493>", line 17, in <module>
controller_0 = qmix.QmixTC(index=0)
File "qmix.py", line 921, in __init__
self._call('LCC_GetChannelHandle', self.index, self._handle)
File "qmix.py", line 937, in _call
func = getattr(self._dll, func_name)
File "C:\Users\Ravikumar\Anaconda2\lib\site-packages\cffi\api.py", line 875, in __getattr__
make_accessor(name)
File "C:\Users\Ravikumar\Anaconda2\lib\site-packages\cffi\api.py", line 870, in make_accessor
raise AttributeError(name)
AttributeError: LCC_GetChannelHandle