def niDigital_PPMU_Source(self, vi, channel_list):
    with self._func_lock:
        if (self.niDigital_PPMU_Source_cfunc is None):
            self.niDigital_PPMU_Source_cfunc = self._get_library_function('niDigital_PPMU_Source')
            self.niDigital_PPMU_Source_cfunc.argtypes = [ViSession, ctypes.POINTER(ViChar)]
            self.niDigital_PPMU_Source_cfunc.restype = ViStatus
    return self.niDigital_PPMU_Source_cfunc(vi, channel_list)
def niDigital_PPMU_Source(self, vi, channel_list):
    with self._func_lock:
        if (self.niDigital_PPMU_Source_cfunc is None):
            self.niDigital_PPMU_Source_cfunc = self._get_library_function('niDigital_PPMU_Source')
            self.niDigital_PPMU_Source_cfunc.argtypes = [ViSession, ctypes.POINTER(ViChar)]
            self.niDigital_PPMU_Source_cfunc.restype = ViStatus
    return self.niDigital_PPMU_Source_cfunc(vi, channel_list)