def __getitem__(self, index):
"""
Indexes a subset of physical channels on this physical channel
collection.
Args:
index: The value of the index. The following index types
are supported:
- str: Name of the physical channel, without the
device name prefix, e.g. 'ai0'. You also can
specify a string that contains a list or range of
names to this input. If you have a list of names,
use the DAQmx Flatten Channel String function to
convert the list to a string.
- int: Index/position of the physical channel in the
collection.
- slice: Range of the indexes/positions of physical
channels in the collection.
Returns:
nidaqmx.system.physical_channel.PhysicalChannel:
Indicates the subset of physical channels indexed.
"""
if isinstance(index, six.integer_types):
return PhysicalChannel(self.channel_names[index])
elif isinstance(index, slice):
return PhysicalChannel(self.channel_names[index])
elif isinstance(index, six.string_types):
return PhysicalChannel('{0}/{1}'.format(self._name, index))
else:
raise DaqError(
'Invalid index type "{0}" used to access collection.'.format(
type(index)), DAQmxErrors.UNKNOWN.value)
def all(self):
"""
nidaqmx.system.physical_channel.PhysicalChannel: Specifies a
physical channel object that represents the entire list of
physical channels on this channel collection.
"""
return PhysicalChannel(flatten_channel_string(self.channel_names))
def physical_channel(self):
"""
:class:`nidaqmx.system.physical_channel.PhysicalChannel`:
Specifies the name of the physical channel upon which this
virtual channel is based.
"""
cfunc = lib_importer.windll.DAQmxGetPhysicalChanName
cfunc.argtypes = [
lib_importer.task_handle, ctypes_byte_str, ctypes.c_char_p,
ctypes.c_uint
]
temp_size = 0
while True:
val = ctypes.create_string_buffer(temp_size)
size_or_code = cfunc(self._handle, self._name, val, temp_size)
if is_string_buffer_too_small(size_or_code):
# Buffer size must have changed between calls; check again.
temp_size = 0
elif size_or_code > 0 and temp_size == 0:
# Buffer size obtained, use to retrieve data.
temp_size = size_or_code
else:
break
check_for_error(size_or_code)
return PhysicalChannel(val.value.decode('ascii'))
def dig_pattern_src(self):
"""
:class:`nidaqmx.system.physical_channel.PhysicalChannel`:
Specifies the physical channels to use for pattern matching.
The order of the physical channels determines the order of
the pattern. If a port is included, the lines within the
port are in ascending order.
"""
cfunc = lib_importer.windll.DAQmxGetDigPatternPauseTrigSrc
cfunc.argtypes = [
lib_importer.task_handle, ctypes.c_char_p, ctypes.c_uint
]
temp_size = 0
while True:
val = ctypes.create_string_buffer(temp_size)
size_or_code = cfunc(self._handle, val, temp_size)
if is_string_buffer_too_small(size_or_code):
# Buffer size must have changed between calls; check again.
temp_size = 0
elif size_or_code > 0 and temp_size == 0:
# Buffer size obtained, use to retrieve data.
temp_size = size_or_code
else:
break
check_for_error(size_or_code)
return PhysicalChannel(val.value.decode('ascii'))
def __reversed__(self):
channel_names = self.channel_names
channel_names.reverse()
for channel_name in channel_names:
yield PhysicalChannel(channel_name)
def __iter__(self):
for channel_name in self.channel_names:
yield PhysicalChannel(channel_name)