def read(self, gpibaddr, count=None, timeout=None):
if count is None:
count = self.max_recv_size
# Change address
self.addr = gpibaddr
# Send reqd request if a GPIB address provided
if not self._auto and gpibaddr is not None:
self.write_raw('++read eoi')
# Get reference to the appropriate buffer
buffer = self._bufferPending[gpibaddr]
# Try to read data, if fail, send read request and try again
status = self.read_raw(count,
buffer,
term_char_en=True,
timeout=timeout)
if status == StatusCode.success_termination_character_read:
term_byte = bytes([self.term_char]) if self.term_char else b''
term_byte_index = buffer.index(term_byte) + 1
elif status == StatusCode.success_max_count_read:
term_byte_index = len(buffer)
elif status == StatusCode.error_timeout:
raise errors.VisaIOError(errors.VI_ERROR_TMO)
else:
raise errors.VisaIOError('Unknown Error')
out = buffer[:term_byte_index].decode().rstrip() # Extract out output
buffer[:term_byte_index] = [] # Remove otuput from buffer
self.logger.debug('PrologiXEthernet.read(): %s', out)
return out
def find_resources(self, session, query):
"""Queries a VISA system to locate the resources associated with a specified interface.
Corresponds to viFindRsrc function of the VISA library.
:param session: Unique logical identifier to a session (unused, just to uniform signatures).
:param query: A regular expression followed by an optional logical expression. Use '?*' for all.
:return: find_list, return_counter, instrument_description, return value of the library call.
:rtype: ViFindList, int, unicode (Py2) or str (Py3), VISAStatus
"""
# For each session type, ask for the list of connected resources and
# merge them into a single list.
resources = sum([
st.list_resources()
for key, st in sessions.Session.iter_valid_session_classes()
], [])
query = query.replace('?*', '.*')
matcher = re.compile(query, re.IGNORECASE)
resources = [res for res in resources if matcher.match(res)]
count = len(resources)
resources = iter(resources)
if count:
return resources, count, next(
resources), constants.StatusCode.success
raise errors.VisaIOError(
errors.StatusCode.error_resource_not_found.value)
def get_visa_attribute(cls, id):
if id == constants.VI_ATTR_TMO_VALUE:
raise errors.VisaIOError(constants.VI_ERROR_NSUP_ATTR)
elif id == constants.VI_ATTR_INTF_NUM:
raise Exception("Long text: aaaaaaaaaaaaaaaaaaaa")
else:
raise Exception("Test")
def after_parsing(self) -> None:
# TODO: board_number not handled
# vx11 expect all timeouts to be expressed in ms and should be integers
try:
self.interface = vxi11.CoreClient(self.parsed.host_address,
self.open_timeout)
except rpc.RPCError:
raise errors.VisaIOError(constants.VI_ERROR_RSRC_NFOUND)
self.lock_timeout = 10000
self.client_id = random.getrandbits(31)
error, link, abort_port, max_recv_size = self.interface.create_link(
self.client_id, 0, self.lock_timeout, self.parsed.lan_device_name)
if error:
raise Exception("error creating link: %d" % error)
self.link = link
self.max_recv_size = min(max_recv_size, 2**30) # 1GB
for name in ("SEND_END_EN", "TERMCHAR", "TERMCHAR_EN"):
attribute = getattr(constants, "VI_ATTR_" + name)
self.attrs[attribute] = attributes.AttributesByID[
attribute].default
def _return_handler(self, ret_value: int, func: Callable,
arguments: tuple) -> Any:
"""Check return values for errors and warnings."""
logger.debug(
"%s%s -> %r",
func.__name__,
_args_to_str(arguments),
ret_value,
extra=self._logging_extra,
)
rv: constants.StatusCode
try:
rv = constants.StatusCode(ret_value)
except ValueError:
rv = cast(constants.StatusCode, ret_value)
self._last_status = rv
# The first argument of almost all registered visa functions is a session.
# We store the error code per session
session = None
if func.__name__ not in ("viFindNext", ):
try:
session = arguments[0]
except KeyError:
raise Exception("Function %r does not seem to be a valid "
"visa function (len args %d)" %
(func, len(arguments)))
# Functions that use the first parameter to get a session value.
if func.__name__ in ("viOpenDefaultRM", ):
# noinspection PyProtectedMember
session = session._obj.value
if isinstance(session, int):
self._last_status_in_session[session] = rv
else:
# Functions that might or might have a session in the first argument.
if func.__name__ not in (
"viClose",
"viGetAttribute",
"viSetAttribute",
"viStatusDesc",
):
raise Exception("Function %r does not seem to be a valid "
"visa function (type args[0] %r)" %
(func, type(session)))
if ret_value < 0:
raise errors.VisaIOError(rv)
if rv in self.issue_warning_on:
if session and ret_value not in self._ignore_warning_in_session[
session]:
warnings.warn(errors.VisaIOWarning(ret_value), stacklevel=2)
return ret_value
def list_resources(self, session: int, query='?*::INSTR') -> List[str]:
resources_list = rname.filter(list(resources), query)
if resources_list:
return resources_list
raise errors.VisaIOError(
errors.StatusCode.error_resource_not_found.value)
def lock(
self,
session: int,
lock_type: constants.Lock,
timeout: int,
requested_key: Optional[str] = None,
) -> Tuple[str, StatusCode]:
"""Establishes an access mode to the specified resources.
Corresponds to viLock function of the VISA library.
Parameters
----------
session : VISASession
Unique logical identifier to a session.
lock_type : constants.Lock
Specifies the type of lock requested.
timeout : int
Absolute time period (in milliseconds) that a resource waits to get
unlocked by the locking session before returning an error.
requested_key : Optional[str], optional
Requested locking key in the case of a shared lock. For an exclusive
lock it should be None.
Returns
-------
Optional[str]
Key that can then be passed to other sessions to share the lock, or
None for an exclusive lock.
StatusCode
Return value of the library call.
"""
if lock_type != constants.Lock.exclusive:
raise NotImplementedError(
f'Only constant.Lock.exclusive supported. ({lock_type})')
if requested_key is not None:
raise NotImplementedError(
f'Requested key is not supported. ({requested_key})')
try:
cur_session = self._sessions[session]
except KeyError as e:
raise errors.VisaIOError(StatusCode.error_connection_lost) from e
acquired = cur_session.resource_lock.acquire(timeout=timeout / 1000)
if not acquired:
raise errors.VisaIOError(StatusCode.error_timeout)
return ('', StatusCode.success)
def _return_handler(self, ret_value, func, arguments):
"""Check return values for errors and warnings.
TODO: THIS IS JUST COPIED PASTED FROM NIVisaLibrary.
Needs to be adapted.
"""
logger.debug('%s%s -> %r',
func.__name__,
_args_to_str(arguments),
ret_value,
extra=self._logging_extra)
try:
ret_value = constants.StatusCode(ret_value)
except ValueError:
pass
self._last_status = ret_value
# The first argument of almost all registered visa functions is a session.
# We store the error code per session
session = None
if func.__name__ not in ('viFindNext', ):
try:
session = arguments[0]
except KeyError:
raise Exception('Function %r does not seem to be a valid '
'visa function (len args %d)' %
(func, len(arguments)))
# Functions that use the first parameter to get a session value.
if func.__name__ in ('viOpenDefaultRM', ):
# noinspection PyProtectedMember
session = session._obj.value
if isinstance(session, integer_types):
self._last_status_in_session[session] = ret_value
else:
# Functions that might or might have a session in the first argument.
if func.__name__ not in ('viClose', 'viGetAttribute',
'viSetAttribute', 'viStatusDesc'):
raise Exception('Function %r does not seem to be a valid '
'visa function (type args[0] %r)' %
(func, type(session)))
if ret_value < 0:
raise errors.VisaIOError(ret_value)
if ret_value in self.issue_warning_on:
if session and ret_value not in self._ignore_warning_in_session[
session]:
warnings.warn(errors.VisaIOWarning(ret_value), stacklevel=2)
return ret_value
def enable_event(
self,
session: int,
event_type: EventType,
mechanism: EventMechanism,
context: None = None,
) -> StatusCode:
"""Enable event occurrences for specified event types and mechanisms in a session.
Corresponds to viEnableEvent function of the VISA library.
Parameters
----------
session : VISASession
Unique logical identifier to a session.
event_type : EventType
Logical event identifier.
mechanism : EventMechanism
Specifies event handling mechanisms to be enabled.
context : None, optional
Unused parameter...
Returns
-------
StatusCode
Return value of the library call.
"""
try:
cur_session = self._sessions[session]
except KeyError as e:
raise errors.VisaIOError(StatusCode.error_connection_lost) from e
if mechanism != EventMechanism.queue:
raise errors.VisaIOError(StatusCode.error_invalid_mechanism)
try:
cur_session.enable_event(event_type)
except EventNotSupportedError as e:
raise errors.VisaIOError(StatusCode.error_invalid_event) from e
except EventNotDisabledError:
# Okay to re-enable event
pass
return StatusCode.success
def wait_on_event(self, session: int, in_event_type: EventType,
timeout: int) -> Tuple[EventType, int, StatusCode]:
"""Wait for an occurrence of the specified event for a given session.
Corresponds to viWaitOnEvent function of the VISA library.
Parameters
----------
session : VISASession
Unique logical identifier to a session.
in_event_type : EventType
Logical identifier of the event(s) to wait for.
timeout : int
Absolute time period in time units that the resource shall wait for
a specified event to occur before returning the time elapsed error.
The time unit is in milliseconds.
Returns
-------
EventType
Logical identifier of the event actually received
int
A handle specifying the unique occurrence of an event
StatusCode
Return value of the library call.
"""
try:
cur_session = self._sessions[session]
except KeyError as e:
raise errors.VisaIOError(StatusCode.error_connection_lost) from e
timeout_td = timedelta(milliseconds=timeout)
try:
cur_session.wait_for_event(event_type=in_event_type,
timeout=timeout_td)
except (EventNotEnabledError, EventNotSupportedError) as e:
raise errors.VisaIOError(StatusCode.error_invalid_event) from e
except EventTimeoutError as e:
raise errors.VisaIOError(StatusCode.error_timeout) from e
return (in_event_type, 0, StatusCode.success)
def discard_events(
self,
session: int,
event_type: EventType,
mechanism: EventMechanism,
) -> StatusCode:
"""Discard event occurrences for a given type and mechanisms in a session.
Corresponds to viDiscardEvents function of the VISA library.
Parameters
----------
session : int
Unique logical identifier to a session.
event_type : constans.EventType
Logical event identifier.
mechanism : EventMechanism
Specifies event handling mechanisms to be discarded.
Returns
-------
StatusCode
Return value of the library call.
"""
try:
cur_session = self._sessions[session]
except KeyError as e:
raise errors.VisaIOError(StatusCode.error_connection_lost) from e
if mechanism != EventMechanism.queue:
return StatusCode.success
try:
cur_session.discard_events(event_type=event_type)
except (EventNotEnabledError, EventNotSupportedError) as e:
raise errors.VisaIOError(StatusCode.error_invalid_event) from e
return StatusCode.success
def list_resources(self, session, query='?*::INSTR'):
"""Returns a tuple of all connected devices matching query.
:param query: regular expression used to match devices.
"""
# For each session type, ask for the list of connected resources and merge them into a single list.
resources = self.devices.list_resources()
resources = rname.filter(resources, query)
if resources:
return resources
raise errors.VisaIOError(
errors.StatusCode.error_resource_not_found.value)
def unlock(self, session: int) -> StatusCode:
"""Relinquish a lock for the specified resource.
Corresponds to viUnlock function of the VISA library.
Parameters
----------
session : VISASession
Unique logical identifier to a session.
Returns
-------
StatusCode
Return value of the library call.
"""
try:
cur_session = self._sessions[session]
except KeyError as e:
raise errors.VisaIOError(StatusCode.error_connection_lost) from e
cur_session.resource_lock.release()
return StatusCode.success
def read(self, session, count):
"""Reads data from device or interface synchronously.
Corresponds to viRead function of the VISA library.
:param session: Unique logical identifier to a session.
:param count: Number of bytes to be read.
:return: data read, return value of the library call.
:rtype: bytes, VISAStatus
"""
# from the session handle, dispatch to the read method of the session object.
try:
ret = self.sessions[session].read(count)
except KeyError:
return 0, StatusCode.error_invalid_object
if ret[1] < 0:
raise errors.VisaIOError(ret[1])
return ret
def write(self, session, data):
"""Writes data to device or interface synchronously.
Corresponds to viWrite function of the VISA library.
:param session: Unique logical identifier to a session.
:param data: data to be written.
:type data: str
:return: Number of bytes actually transferred, return value of the library call.
:rtype: int, VISAStatus
"""
# from the session handle, dispatch to the write method of the session object.
try:
ret = self.sessions[session].write(data)
except KeyError:
return 0, StatusCode.error_invalid_object
if ret[1] < 0:
raise errors.VisaIOError(ret[1])
return ret
def read(self, session, count):
"""Reads data from device or interface synchronously.
Corresponds to viRead function of the VISA library.
:param session: Unique logical identifier to a session.
:param count: Number of bytes to be read.
:return: data read, return value of the library call.
:rtype: bytes, :class:`pyvisa.constants.StatusCode`
"""
try:
sess = self.sessions[session]
except KeyError:
return b'', constants.StatusCode.error_invalid_object
try:
chunk, status = sess.read(count)
if status == constants.StatusCode.error_timeout:
raise errors.VisaIOError(constants.VI_ERROR_TMO)
return chunk, status
except AttributeError:
return b'', constants.StatusCode.error_nonsupported_operation
def disable_event(
self,
session: int,
event_type: EventType,
mechanism: EventMechanism,
) -> StatusCode:
"""Disable notification for an event type(s) via the specified mechanism(s).
Corresponds to viDisableEvent function of the VISA library.
Parameters
----------
session : int
Unique logical identifier to a session.
event_type : EventType
Event type.
mechanism : EventMechanism
Event handling mechanisms to be disabled.
Returns
-------
StatusCode
Return value of the library call.
"""
try:
cur_session = self._sessions[session]
except KeyError as e:
raise errors.VisaIOError(StatusCode.error_connection_lost) from e
if mechanism != EventMechanism.queue:
return StatusCode.success
try:
cur_session.disable_event(event_type=event_type)
except (EventNotEnabledError, EventNotSupportedError):
# Okay to re-disable an event or disable unsupported event
pass
return StatusCode.success
def list_resources(self, session, query='?*::INSTR'):
"""Returns a tuple of all connected devices matching query.
:param query: regular expression used to match devices.
"""
# For each session type, ask for the list of connected resources and
# merge them into a single list.
resources = sum([
st.list_resources()
for key, st in sessions.Session.iter_valid_session_classes()
], [])
query = query.replace('?*', '.*')
matcher = re.compile(query, re.IGNORECASE)
resources = tuple(res for res in resources if matcher.match(res))
if resources:
return resources
raise errors.VisaIOError(
errors.StatusCode.error_resource_not_found.value)
def test_VisaIOError(self):
self._test_pickle_unpickle(errors.VisaIOError(0))
def false_read(session, size):
raise errors.VisaIOError(constants.VI_ERROR_ABORT)
