def test_handling_malformed_binary(self):
containers = (list, tuple) + ((np.array, np.ndarray) if np else ())
# Use this to generate malformed data which should in theory be
# impossible
class DumbBytes(bytes):
def __len__(self):
return 10
for container in containers:
with pytest.raises(ValueError) as e:
util.from_binary_block(DumbBytes(b"\x00\x00\x00"), container=container)
assert (
"malformed" if container in (list, tuple) else "buffer" in e.exconly()
)
def query_binary_values(self,
command,
datatype='f',
container=np.array,
is_big_endian=False,
bufsize=None):
"""Write a string message to device and read binary values, which are
returned as iterable. Uses a pyvisa utility function.
Args:
command: String command sent to instrument.
values: Data to be sent to instrument.
datatype: Format string for single element.
container: Iterable to return number of as.
is_big_endian: Bool indicating endianness.
Returns:
Iterable of data values to be retuned
"""
if bufsize is None:
bufsize = self.bufsize
self.write(command, bufsize=bufsize)
block = self.read_raw()
return from_binary_block(block,
datatype=datatype,
is_big_endian=is_big_endian,
container=container)
def parse_binary_responses(self, kind, res_in):
if kind == 'fetch':
glob_offset = 0
for idx, key in enumerate(self.fetch_kinds[:3]):
offset, length = util.parse_ieee_block_header(res_in)
glob_offset += offset
self.last_reading[key] = util.from_binary_block(
res_in,
offset=glob_offset,
data_length=length,
datatype='i',
is_big_endian=True,
container=np.array)
glob_offset += length + 4
glob_offset -= 3 # separation between last binary block and timestamp string is only one byte isntead of 4
parsed = res_in[glob_offset:].split(b';')
for idx, key in enumerate(self.fetch_kinds[3:]):
self.last_reading[key] = self.str_conv(
parsed[idx].decode('ascii'), key)
ending = parsed[-1].decode('ascii')
if ending.split('\n')[0] == '4':
res = self.visa_res.query(':SYSTEM:ERROR?;*STB?')
self.errors.append(res)
while res[0] != '0':
print("Error code: {}".format(res))
res = self.visa_res.query(':SYSTEM:ERROR?;*STB?')
self.errors.append(res)
