def _format_binary_values(self,
values,
datatype='f',
is_big_endian=False,
header_fmt="ieee"):
"""Format values in binary format, used internally in :meth:`.write_binary_values`.
:param values: data to be written to the device.
:param datatype: the format string for a single element. See struct module.
:param is_big_endian: boolean indicating endianess.
:param header_fmt: Format of the header prefixing the data ("ieee", "hp", "empty").
:return: binary string.
:rtype: bytes
"""
if header_fmt == "ieee":
block = to_ieee_block(values, datatype, is_big_endian)
elif header_fmt == "hp":
block = to_hp_block(values, datatype, is_big_endian)
elif header_fmt == "empty":
block = to_binary_block(values, b"", datatype, is_big_endian)
else:
raise ValueError("Unsupported header_fmt: %s" % header_fmt)
return block
def test_ieee_noninteger(self):
values = [val + 0.5 for val in range(100)]
containers = (list, tuple) #+ ((np.asarray,) if np else ())
for fmt in 'fd':
for endi in (True, False):
for cont in containers:
conv = cont(values)
block = util.to_ieee_block(conv, fmt, endi)
parsed = util.from_ieee_block(block, fmt, endi, cont)
self.assertEqual(conv, parsed)
def test_ieee_noninteger(self):
values = [val + 0.5 for val in range(100)]
containers = (list, tuple) #+ ((np.asarray,) if np else ())
for fmt in 'fd':
for endi in (True, False):
for cont in containers:
conv = cont(values)
msg = 'fmt=%s, endianness=%s, container=%s' % (fmt, endi, cont.__name__)
try:
block = util.to_ieee_block(conv, fmt, endi)
parsed = util.from_ieee_block(block, fmt, endi, cont)
except Exception as e:
raise Exception(msg + '\n' + repr(e))
self.assertEqual(conv, parsed, msg)
def test_ieee_noninteger(self):
values = [val + 0.5 for val in range(99)]
containers = (list, tuple) #+ ((np.asarray,) if np else ())
for fmt in 'fd':
for endi in (True, False):
for cont in containers:
conv = cont(values)
msg = 'fmt=%s, endianness=%s, container=%s' % (fmt, endi, cont.__name__)
try:
block = util.to_ieee_block(conv, fmt, endi)
parsed = util.from_ieee_block(block, fmt, endi, cont)
except Exception as e:
raise Exception(msg + '\n' + repr(e))
self.assertEqual(conv, parsed, msg)
def write_binary_values(self,
command,
values,
datatype='f',
is_big_endian=False):
"""Write a string message to device followed by values in binary IEEE
format using a pyvisa utility function.)
Args:
command: String command sent to instrument.
values: Data to be sent to instrument.
datatype: Format string for single element.
is_big_endian: Bool indicating endianness.
Returns:
Number of bytes written to instrument.
"""
data = to_ieee_block(values,
datatype=datatype,
is_big_endian=is_big_endian)
return self.write_raw(command.encode() + data)