diff options
| -rw-r--r-- | pyvisa/ctwrapper/__init__.py | 9 | ||||
| -rw-r--r-- | pyvisa/ctwrapper/attributes.py | 4 | ||||
| -rw-r--r-- | pyvisa/ctwrapper/functions.py | 24 | ||||
| -rw-r--r-- | pyvisa/ctwrapper/highlevel.py | 125 | ||||
| -rw-r--r-- | pyvisa/ctwrapper/types.py | 6 | ||||
| -rw-r--r-- | pyvisa/highlevel.py | 1441 | ||||
| -rw-r--r-- | visa.py | 2 |
7 files changed, 1439 insertions, 172 deletions
diff --git a/pyvisa/ctwrapper/__init__.py b/pyvisa/ctwrapper/__init__.py index d13f0b9..931c99a 100644 --- a/pyvisa/ctwrapper/__init__.py +++ b/pyvisa/ctwrapper/__init__.py @@ -1,9 +1,9 @@ # -*- coding: utf-8 -*- """ - pyvisa.wrapper - ~~~~~~~~~~~~~~ + pyvisa.ctwrapper + ~~~~~~~~~~~~~~~~ - ctypes wrapper for VISA library. + ctypes wrapper for NI-VISA library. This file is part of PyVISA. @@ -23,8 +23,9 @@ else: from . import types -from .functions import * +from .highlevel import NIVisaLibrary +WRAPPER_CLASS = NIVisaLibrary # On Linux, find Library returns the name not the path. # This excerpt provides a modified find_library. diff --git a/pyvisa/ctwrapper/attributes.py b/pyvisa/ctwrapper/attributes.py index 0246ca6..adfa5f8 100644 --- a/pyvisa/ctwrapper/attributes.py +++ b/pyvisa/ctwrapper/attributes.py @@ -1,7 +1,7 @@ # -*- coding: utf-8 -*- """ - pyvisa.wrapper.attributes - ~~~~~~~~~~~~~~~~~~~~~~~~~ + pyvisa.ctwrapper.attributes + ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Defines VPP 4.3.2 attribute data. diff --git a/pyvisa/ctwrapper/functions.py b/pyvisa/ctwrapper/functions.py index 33c9fd6..e973fc9 100644 --- a/pyvisa/ctwrapper/functions.py +++ b/pyvisa/ctwrapper/functions.py @@ -1,9 +1,9 @@ # -*- coding: utf-8 -*- """ - pyvisa.wrapper.functions - ~~~~~~~~~~~~~~~~~~~~~~~~ + pyvisa.ctwrapper.functions + ~~~~~~~~~~~~~~~~~~~~~~~~~~ - Defines VPP 4.3.2 wrapping functions, adding signatures to the library. + Defines VPP 4.3.2 wrapping functions using ctypes, adding signatures to the library. This file is part of PyVISA. @@ -13,13 +13,15 @@ from __future__ import division, unicode_literals, print_function, absolute_import -import collections import warnings from ctypes import (byref, c_void_p, c_double, c_long, POINTER, create_string_buffer) -from . import FUNCTYPE +from ..highlevel import ResourceInfo +from ..util import get_library_paths from ..constants import * + +from . import FUNCTYPE from .types import * from .attributes import attributes @@ -47,11 +49,6 @@ __all__ = ["visa_functions", 'set_signatures'] + visa_functions VI_SPEC_VERSION = 0x00300000 -#: Resource extended information -ResourceInfo = collections.namedtuple('ResourceInfo', - 'interface_type interface_board_number ' - 'resource_class resource_name alias') - def set_user_handle_type(library, user_handle): """Set the type of the user handle to install and uninstall handler signature. @@ -94,6 +91,7 @@ def set_signatures(library, errcheck=None): def _internal(function_name, argtypes, required=False): try: set_signature(library, function_name, argtypes, restype, errcheck_) + # noinspection PyProtectedMember library._functions.append(function_name) except AttributeError: if required: @@ -425,7 +423,7 @@ def discard_events(library, session, event_type, mechanism): return library.viDiscardEvents(session, event_type, mechanism) -def enable_event(library, session, event_type, mechanism, context=VI_NULL): +def enable_event(library, session, event_type, mechanism, context=None): """Enable event occurrences for specified event types and mechanisms in a session. Corresponds to viEnableEvent function of the VISA library. @@ -439,7 +437,9 @@ def enable_event(library, session, event_type, mechanism, context=VI_NULL): :return: return value of the library call. :rtype: VISAStatus """ - if context != VI_NULL: + if context is None: + context = VI_NULL + elif context != VI_NULL: warnings.warn('In enable_event, context will be set VI_NULL.') context = VI_NULL # according to spec VPP-4.3, section 3.7.3.1 return library.viEnableEvent(session, event_type, mechanism, context) diff --git a/pyvisa/ctwrapper/highlevel.py b/pyvisa/ctwrapper/highlevel.py new file mode 100644 index 0000000..4ae0d3c --- /dev/null +++ b/pyvisa/ctwrapper/highlevel.py @@ -0,0 +1,125 @@ +# -*- coding: utf-8 -*- +""" + pyvisa.ctwrapper.highlevel + ~~~~~~~~~~~~~~~~~~~~~~~~~~ + + Highlevel wrapper of the VISA Library. + + This file is part of PyVISA. + + :copyright: 2014 by PyVISA Authors, see AUTHORS for more details. + :license: MIT, see LICENSE for more details. +""" + +from __future__ import division, unicode_literals, print_function, absolute_import + +from .. import constants, errors, highlevel, logger +from ..compat import integer_types + +from . import Library +from . import functions + +def add_visa_methods(aclass): + for method in functions.visa_functions: + setattr(aclass, method, getattr(functions, method)) + return aclass + + +def _args_to_str(args): + out = [] + for arg in args: + try: + # noinspection PyProtectedMember + out.append(str(arg._obj)) + except Exception: + out.append(arg) + return tuple(out) + + +@add_visa_methods +class NIVisaLibrary(highlevel.VisaLibraryBase): + """High level NI-VISA Library wrapper using ctypes. + + The easiest way to instantiate the library is to let `pyvisa` find the + right one for you. This looks first in your configuration file (~/.pyvisarc). + If it fails, it uses `ctypes.util.find_library` to try to locate a library + in a way similar to what the compiler does: + + >>> visa_library = NIVisaLibrary() + + But you can also specify the path: + + >>> visa_library = NIVisaLibrary('/my/path/visa.so') + + :param library_path: path of the VISA library. + """ + + def __new__(cls, library_path): + if library_path in cls._registry: + return cls._registry[library_path] + + try: + lib = Library(library_path) + except OSError as exc: + raise errors.LibraryError.from_exception(exc, library_path) + + obj = super(highlevel.VisaLibraryBase, cls).__new__(cls, library_path) + obj.lib = lib + + # Set the argtypes, restype and errcheck for each function + # of the visa library. Additionally store in `_functions` the + # name of the functions. + functions.set_signatures(obj.lib, errcheck=obj._return_handler) + + # Set the library functions as attributes of the object. + for method_name in getattr(obj.lib, '_functions', []): + setattr(obj, method_name, getattr(obj.lib, method_name)) + + return obj + + def _return_handler(self, ret_value, func, arguments): + """Check return values for errors and warnings. + """ + + 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 diff --git a/pyvisa/ctwrapper/types.py b/pyvisa/ctwrapper/types.py index 2445319..1e205f7 100644 --- a/pyvisa/ctwrapper/types.py +++ b/pyvisa/ctwrapper/types.py @@ -1,9 +1,9 @@ # -*- coding: utf-8 -*- """ - pyvisa.wrapper.types - ~~~~~~~~~~~~~~~~~~~~ + pyvisa.ctwrapper.types + ~~~~~~~~~~~~~~~~~~~~~~ - VISA VPP-4.3 data types (VPP-4.3.2 spec, section 3). + VISA VPP-4.3 data types (VPP-4.3.2 spec, section 3) using ctypes constants. This file is part of PyVISA. diff --git a/pyvisa/highlevel.py b/pyvisa/highlevel.py index 69e2631..d3ff5a3 100644 --- a/pyvisa/highlevel.py +++ b/pyvisa/highlevel.py @@ -13,66 +13,28 @@ from __future__ import division, unicode_literals, print_function, absolute_import +import abc import contextlib +import collections +import pkgutil import warnings from collections import defaultdict from . import logger from . import constants -from . import ctwrapper from . import errors -from .util import get_library_paths -from .compat import integer_types +from . import util +#: Resource extended information +ResourceInfo = collections.namedtuple('ResourceInfo', + 'interface_type interface_board_number ' + 'resource_class resource_name alias') -def _args_to_str(args): - out = [] - for arg in args: - try: - out.append(str(arg._obj)) - except Exception: - out.append(arg) - return tuple(out) - +class VisaLibraryBase(object): + """Base class for VISA library wrappers. -def add_visa_methods(wrapper_module): - """Decorator factory to add methods in `wrapper_module.visa_functions` - iterable to a class. - - :param wrapper_module: the python module/package that wraps the visa library. - """ - def _internal(aclass): - aclass._wrapper_module = wrapper_module - methods = wrapper_module.visa_functions - for method in methods: - if hasattr(aclass, method): - setattr(aclass, '_' + method, getattr(wrapper_module, method)) - else: - setattr(aclass, method, getattr(wrapper_module, method)) - return aclass - return _internal - - -@add_visa_methods(ctwrapper) -class VisaLibrary(object): - """High level VISA Library wrapper. - - The easiest way to instantiate the library is to let `pyvisa` find the - right one for you. This looks first in your configuration file (~/.pyvisarc). - If it fails, it uses `ctypes.util.find_library` to try to locate a library - in a way similar to what the compiler does: - - >>> visa_library = VisaLibrary() - - But you can also specify the path: - - >>> visa_library = VisaLibrary('/my/path/visa.so') - - Or use the `from_paths` constructor if you want to try multiple paths: - - >>> visa_library = VisaLibrary.from_paths(['/my/path/visa.so', '/maybe/this/visa.so']) - - :param library_path: path of the VISA library. + Derived classes must have a constructor that accept a single element + following the syntax of :open_visa_library: """ #: Default ResourceManager instance for this library. @@ -87,67 +49,28 @@ class VisaLibrary(object): #: Maps session handle to warnings to ignore _ignore_warning_in_session = defaultdict(set) - @classmethod - def from_paths(cls, *paths): - """Helper constructor that tries to instantiate VisaLibrary from an - iterable of possible library paths. - """ - errs = [] - for path in paths: - try: - return cls(path) - except OSError as e: - logger.debug('Could not open VISA library %s: %s', path, str(e)) - errs.append(str(e)) - else: - raise OSError('Could not open VISA library:\n' + '\n'.join(errs)) - - def __new__(cls, library_path=None): - if library_path is None: - paths = get_library_paths(cls._wrapper_module) - if not paths: - raise OSError('Could not found VISA library. ' - 'Please install VISA or pass its location as an argument.') - return cls.from_paths(*paths) - else: - if library_path in cls._registry: - return cls._registry[library_path] - - cls._registry[library_path] = obj = super(VisaLibrary, cls).__new__(cls) + def __init__(self, library_path): + super(VisaLibraryBase, self).__init__() - try: - obj.lib = cls._wrapper_module.Library(library_path) - except OSError as exc: - raise errors.LibraryError.from_exception(exc, library_path) + self.library_path = library_path - obj.library_path = library_path + self._registry[library_path] = self logger.debug('Created library wrapper for %s', library_path) - # Set the argtypes, restype and errcheck for each function - # of the visa library. Additionally store in `_functions` the - # name of the functions. - cls._wrapper_module.set_signatures(obj.lib, errcheck=obj._return_handler) - - # Set the library functions as attributes of the object. - for method_name in getattr(obj.lib, '_functions', []): - setattr(obj, method_name, getattr(obj.lib, method_name)) - #: Error codes on which to issue a warning. - obj.issue_warning_on = set(errors.default_warnings) + self.issue_warning_on = set(errors.default_warnings) #: Contains all installed event handlers. #: Its elements are tuples with three elements: The handler itself (a Python #: callable), the user handle (as a ct object) and the handler again, this #: time as a ct object created with CFUNCTYPE. - obj.handlers = defaultdict(list) + self.handlers = defaultdict(list) #: Last return value of the library. - obj._last_status = 0 + self._last_status = 0 - obj._logging_extra = {'library_path': obj.library_path} - - return obj + self._logging_extra = {'library_path': self.library_path} def __str__(self): return 'Visa Library at %s' % self.library_path @@ -179,52 +102,6 @@ class VisaLibrary(object): self._resource_manager = ResourceManager(self) return self._resource_manager - def _return_handler(self, ret_value, func, arguments): - """Check return values for errors and warnings. - """ - - 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', ): - 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 - @contextlib.contextmanager def ignore_warning(self, session, *warnings_constants): """A session dependent context for ignoring warnings @@ -236,7 +113,7 @@ class VisaLibrary(object): yield self._ignore_warning_in_session[session].difference_update(warnings_constants) - def install_handler(self, session, event_type, handler, user_handle=None): + def install_visa_handler(self, session, event_type, handler, user_handle=None): """Installs handlers for event callbacks. :param session: Unique logical identifier to a session. @@ -247,14 +124,14 @@ class VisaLibrary(object): :returns: user handle (a ctypes object) """ try: - new_handler = self._install_handler(self.lib, session, event_type, handler, user_handle) + new_handler = self.install_handler(session, event_type, handler, user_handle) except TypeError as e: raise errors.VisaTypeError(str(e)) self.handlers[session].append(new_handler) return new_handler[1] - def uninstall_handler(self, session, event_type, handler, user_handle=None): + def uninstall_visa_handler(self, session, event_type, handler, user_handle=None): """Uninstalls handlers for events. :param session: Unique logical identifier to a session. @@ -269,7 +146,1266 @@ class VisaLibrary(object): break else: raise errors.UnknownHandler(event_type, handler, user_handle) - self._uninstall_handler(self.lib, session, event_type, handler, user_handle) + self.uninstall_handler(session, event_type, handler, user_handle) + + def read_memory(self, session, space, offset, width, extended=False): + """Reads in an 8-bit, 16-bit, 32-bit, or 64-bit value from the specified memory space and offset. + + Corresponds to viIn* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param width: Number of bits to read. + :param extended: Use 64 bits offset independent of the platform. + :return: Data read from memory, return value of the library call. + :rtype: int, VISAStatus + """ + if width == 8: + return self.in_8(session, space, offset, extended) + elif width == 16: + return self.in_16(session, space, offset, extended) + elif width == 32: + return self.in_32(session, space, offset, extended) + elif width == 64: + return self.in_64(session, space, offset, extended) + + raise ValueError('%s is not a valid size. Valid values are 8, 16, 32 or 64' % width) + + def write_memory(self, session, space, offset, data, width, extended=False): + """Write in an 8-bit, 16-bit, 32-bit, value to the specified memory space and offset. + + Corresponds to viOut* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param data: Data to write to bus. + :param width: Number of bits to read. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + if width == 8: + return self.out_8(session, space, offset, data, extended) + elif width == 16: + return self.out_16(session, space, offset, data, extended) + elif width == 32: + return self.out_32(session, space, offset, data, extended) + + raise ValueError('%s is not a valid size. Valid values are 8, 16 or 32' % width) + + def move_in(self, session, space, offset, length, width, extended=False): + """Moves a block of data to local memory from the specified address space and offset. + + Corresponds to viMoveIn* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param width: Number of bits to read per element. + :param extended: Use 64 bits offset independent of the platform. + :return: Data read from the bus, return value of the library call. + :rtype: list, VISAStatus + """ + if width == 8: + return self.move_in_8(session, space, offset, length, extended) + elif width == 16: + return self.move_in_16(session, space, offset, length, extended) + elif width == 32: + return self.move_in_32(session, space, offset, length, extended) + elif width == 64: + return self.move_in_64(session, space, offset, length, extended) + + raise ValueError('%s is not a valid size. Valid values are 8, 16, 32 or 64' % width) + + def move_out(self, session, space, offset, length, data, width, extended=False): + """Moves a block of data from local memory to the specified address space and offset. + + Corresponds to viMoveOut* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param data: Data to write to bus. + :param width: Number of bits to read per element. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + if width == 8: + return self.move_out_8(session, space, offset, length, data, extended) + elif width == 16: + return self.move_out_16(session, space, offset, length, data, extended) + elif width == 32: + return self.move_out_32(session, space, offset, length, data, extended) + elif width == 64: + return self.move_out_64(session, space, offset, length, data, extended) + + raise ValueError('%s is not a valid size. Valid values are 8, 16, 32 or 64' % width) + + def peek(self, session, address, width): + """Read an 8, 16 or 32-bit value from the specified address. + + Corresponds to viPeek* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param address: Source address to read the value. + :param width: Number of bits to read. + :return: Data read from bus, return value of the library call. + :rtype: bytes, VISAStatus + """ + + if width == 8: + return self.peek_8(session, address) + elif width == 16: + return self.peek_16(session, address) + elif width == 32: + return self.peek_32(session, address) + elif width == 64: + return self.peek_64(session, address) + + raise ValueError('%s is not a valid size. Valid values are 8, 16, 32 or 64' % width) + + def poke(self, session, address, width, data): + """Writes an 8, 16 or 32-bit value from the specified address. + + Corresponds to viPoke* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param address: Source address to read the value. + :param width: Number of bits to read. + :param data: Data to be written to the bus. + :return: return value of the library call. + :rtype: VISAStatus + """ + + if width == 8: + return self.poke_8(session, address, data) + elif width == 16: + return self.poke_16(session, address, data) + elif width == 32: + return self.poke_32(session, address, data) + + raise ValueError('%s is not a valid size. Valid values are 8, 16 or 32' % width) + + # Methods that VISA Library implementations must implement + + def assert_interrupt_signal(self, session, mode, status_id): + """Asserts the specified interrupt or signal. + + Corresponds to viAssertIntrSignal function of the VISA library. + + :param session: Unique logical identifier to a session. + :param mode: How to assert the interrupt. (Constants.ASSERT*) + :param status_id: This is the status value to be presented during an interrupt acknowledge cycle. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def assert_trigger(self, session, protocol): + """Asserts software or hardware trigger. + + Corresponds to viAssertTrigger function of the VISA library. + + :param session: Unique logical identifier to a session. + :param protocol: Trigger protocol to use during assertion. (Constants.PROT*) + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def assert_utility_signal(self, session, line): + """Asserts or deasserts the specified utility bus signal. + + Corresponds to viAssertUtilSignal function of the VISA library. + + :param session: Unique logical identifier to a session. + :param line: specifies the utility bus signal to assert. (Constants.UTIL_ASSERT*) + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def buffer_read(self, session, count): + """Reads data from device or interface through the use of a formatted I/O read buffer. + + Corresponds to viBufRead 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 + """ + raise NotImplementedError + + def buffer_write(self, session, data): + """Writes data to a formatted I/O write buffer synchronously. + + Corresponds to viBufWrite function of the VISA library. + + :param session: Unique logical identifier to a session. + :param data: data to be written. + :type data: bytes + :return: number of written bytes, return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + + def clear(self, session): + """Clears a device. + + Corresponds to viClear function of the VISA library. + + :param session: Unique logical identifier to a session. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def close(self, session): + """Closes the specified session, event, or find list. + + Corresponds to viClose function of the VISA library. + + :param session: Unique logical identifier to a session, event, or find list. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def disable_event(self, session, event_type, mechanism): + """Disables notification of the specified event type(s) via the specified mechanism(s). + + Corresponds to viDisableEvent function of the VISA library. + + :param session: Unique logical identifier to a session. + :param event_type: Logical event identifier. + :param mechanism: Specifies event handling mechanisms to be disabled. + (Constants.QUEUE, .Handler, .SUSPEND_HNDLR, .ALL_MECH) + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def discard_events(self, session, event_type, mechanism): + """Discards event occurrences for specified event types and mechanisms in a session. + + Corresponds to viDiscardEvents function of the VISA library. + + :param session: Unique logical identifier to a session. + :param event_type: Logical event identifier. + :param mechanism: Specifies event handling mechanisms to be disabled. + (Constants.QUEUE, .Handler, .SUSPEND_HNDLR, .ALL_MECH) + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def enable_event(self, session, event_type, mechanism, context=None): + """Enable event occurrences for specified event types and mechanisms in a session. + + Corresponds to viEnableEvent function of the VISA library. + + :param session: Unique logical identifier to a session. + :param event_type: Logical event identifier. + :param mechanism: Specifies event handling mechanisms to be disabled. + (Constants.QUEUE, .Handler, .SUSPEND_HNDLR) + :param context: + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def find_next(self, find_list): + """Returns the next resource from the list of resources found during a previous call to find_resources(). + + Corresponds to viFindNext function of the VISA library. + + :param find_list: Describes a find list. This parameter must be created by find_resources(). + :return: Returns a string identifying the location of a device, return value of the library call. + :rtype: unicode (Py2) or str (Py3), VISAStatus + """ + raise NotImplementedError + + 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 + """ + raise NotImplementedError + + def flush(self, session, mask): + """Manually flushes the specified buffers associated with formatted I/O operations and/or serial communication. + + Corresponds to viFlush function of the VISA library. + + :param session: Unique logical identifier to a session. + :param mask: Specifies the action to be taken with flushing the buffer. + (Constants.READ*, .WRITE*, .IO*) + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def get_attribute(self, session, attribute): + """Retrieves the state of an attribute. + + Corresponds to viGetAttribute function of the VISA library. + + :param session: Unique logical identifier to a session, event, or find list. + :param attribute: Resource attribute for which the state query is made (see Attributes.*) + :return: The state of the queried attribute for a specified resource, return value of the library call. + :rtype: unicode (Py2) or str (Py3), list or other type, VISAStatus + """ + raise NotImplementedError + + def gpib_command(self, session, data): + """Write GPIB command bytes on the bus. + + Corresponds to viGpibCommand function of the VISA library. + + :param session: Unique logical identifier to a session. + :param data: data tor write. + :type data: bytes + :return: Number of written bytes, return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + + def gpib_control_atn(self, session, mode): + """Specifies the state of the ATN line and the local active controller state. + + Corresponds to viGpibControlATN function of the VISA library. + + :param session: Unique logical identifier to a session. + :param mode: Specifies the state of the ATN line and optionally the local active controller state. + (Constants.GPIB_ATN*) + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def gpib_control_ren(self, session, mode): + """Controls the state of the GPIB Remote Enable (REN) interface line, and optionally the remote/local + state of the device. + + Corresponds to viGpibControlREN function of the VISA library. + + :param session: Unique logical identifier to a session. + :param mode: Specifies the state of the REN line and optionally the device remote/local state. + (Constants.GPIB_REN*) + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def gpib_pass_control(self, session, primary_address, secondary_address): + """Tell the GPIB device at the specified address to become controller in charge (CIC). + + Corresponds to viGpibPassControl function of the VISA library. + + :param session: Unique logical identifier to a session. + :param primary_address: Primary address of the GPIB device to which you want to pass control. + :param secondary_address: Secondary address of the targeted GPIB device. + If the targeted device does not have a secondary address, + this parameter should contain the value Constants.NO_SEC_ADDR. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def gpib_send_ifc(self, session): + """Pulse the interface clear line (IFC) for at least 100 microseconds. + + Corresponds to viGpibSendIFC function of the VISA library. + + :param session: Unique logical identifier to a session. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def in_8(self, session, space, offset, extended=False): + """Reads in an 8-bit value from the specified memory space and offset. + + Corresponds to viIn8* function of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param extended: Use 64 bits offset independent of the platform. + :return: Data read from memory, return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + + def in_16(self, session, space, offset, extended=False): + """Reads in an 16-bit value from the specified memory space and offset. + + Corresponds to viIn16* function of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param extended: Use 64 bits offset independent of the platform. + :return: Data read from memory, return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + + def in_32(self, session, space, offset, extended=False): + """Reads in an 32-bit value from the specified memory space and offset. + + Corresponds to viIn32* function of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param extended: Use 64 bits offset independent of the platform. + :return: Data read from memory, return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + + def in_64(self, session, space, offset, extended=False): + """Reads in an 64-bit value from the specified memory space and offset. + + Corresponds to viIn64* function of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param extended: Use 64 bits offset independent of the platform. + :return: Data read from memory, return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + + def install_handler(self, session, event_type, handler, user_handle): + """Installs handlers for event callbacks. + + Corresponds to viInstallHandler function of the VISA library. + + :param session: Unique logical identifier to a session. + :param event_type: Logical event identifier. + :param handler: Interpreted as a valid reference to a handler to be installed by a client application. + :param user_handle: A value specified by an application that can be used for identifying handlers + uniquely for an event type. + :returns: a handler descriptor which consists of three elements: + - handler (a python callable) + - user handle (a ctypes object) + - ctypes handler (ctypes object wrapping handler) + and return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + + def lock(self, session, lock_type, timeout, requested_key=None): + """Establishes an access mode to the specified resources. + + Corresponds to viLock function of the VISA library. + + :param session: Unique logical identifier to a session. + :param lock_type: Specifies the type of lock requested, either Constants.EXCLUSIVE_LOCK or Constants.SHARED_LOCK. + :param timeout: Absolute time period (in milliseconds) that a resource waits to get unlocked by the + locking session before returning an error. + :param requested_key: This parameter is not used and should be set to VI_NULL when lockType is VI_EXCLUSIVE_LOCK. + :return: access_key that can then be passed to other sessions to share the lock, return value of the library call. + :rtype: str, VISAStatus + """ + + + def map_address(self, session, map_space, map_base, map_size, + access=False, suggested=None): + """Maps the specified memory space into the process's address space. + + Corresponds to viMapAddress function of the VISA library. + + :param session: Unique logical identifier to a session. + :param map_space: Specifies the address space to map. (Constants.*SPACE*) + :param map_base: Offset (in bytes) of the memory to be mapped. + :param map_size: Amount of memory to map (in bytes). + :param access: + :param suggested: If not Constants.NULL (0), the operating system attempts to map the memory to the address + specified in suggested. There is no guarantee, however, that the memory will be mapped to + that address. This operation may map the memory into an address region different from + suggested. + + :return: address in your process space where the memory was mapped, return value of the library call. + :rtype: address, VISAStatus + """ + raise NotImplementedError + + def map_trigger(self, session, trigger_source, trigger_destination, mode): + """Map the specified trigger source line to the specified destination line. + + Corresponds to viMapTrigger function of the VISA library. + + :param session: Unique logical identifier to a session. + :param trigger_source: Source line from which to map. (Constants.TRIG*) + :param trigger_destination: Destination line to which to map. (Constants.TRIG*) + :param mode: + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def memory_allocation(self, session, size, extended=False): + """Allocates memory from a resource's memory region. + + Corresponds to viMemAlloc* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param size: Specifies the size of the allocation. + :param extended: Use 64 bits offset independent of the platform. + :return: offset of the allocated memory, return value of the library call. + :rtype: offset, VISAStatus + """ + raise NotImplementedError + + def memory_free(self, session, offset, extended=False): + """Frees memory previously allocated using the memory_allocation() operation. + + Corresponds to viMemFree* function of the VISA library. + + :param session: Unique logical identifier to a session. + :param offset: Offset of the memory to free. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def move(self, session, source_space, source_offset, source_width, destination_space, + destination_offset, destination_width, length): + """Moves a block of data. + + Corresponds to viMove function of the VISA library. + + :param session: Unique logical identifier to a session. + :param source_space: Specifies the address space of the source. + :param source_offset: Offset of the starting address or register from which to read. + :param source_width: Specifies the data width of the source. + :param destination_space: Specifies the address space of the destination. + :param destination_offset: Offset of the starting address or register to which to write. + :param destination_width: Specifies the data width of the destination. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def move_asynchronously(self, session, source_space, source_offset, source_width, + destination_space, destination_offset, + destination_width, length): + """Moves a block of data asynchronously. + + Corresponds to viMoveAsync function of the VISA library. + + :param session: Unique logical identifier to a session. + :param source_space: Specifies the address space of the source. + :param source_offset: Offset of the starting address or register from which to read. + :param source_width: Specifies the data width of the source. + :param destination_space: Specifies the address space of the destination. + :param destination_offset: Offset of the starting address or register to which to write. + :param destination_width: Specifies the data width of the destination. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :return: Job identifier of this asynchronous move operation, return value of the library call. + :rtype: jobid, VISAStatus + """ + raise NotImplementedError + + def move_in_8(self, session, space, offset, length, extended=False): + """Moves an 8-bit block of data from the specified address space and offset to local memory. + + Corresponds to viMoveIn8* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param extended: Use 64 bits offset independent of the platform. + :return: Data read from the bus, return value of the library call. + :rtype: list, VISAStatus + """ + raise NotImplementedError + + def move_in_16(self, session, space, offset, length, extended=False): + """Moves an 16-bit block of data from the specified address space and offset to local memory. + + Corresponds to viMoveIn16* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param extended: Use 64 bits offset independent of the platform. + :return: Data read from the bus, return value of the library call. + :rtype: list, VISAStatus + """ + raise NotImplementedError + + def move_in_32(self, session, space, offset, length, extended=False): + """Moves an 32-bit block of data from the specified address space and offset to local memory. + + Corresponds to viMoveIn32* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param extended: Use 64 bits offset independent of the platform. + :return: Data read from the bus, return value of the library call. + :rtype: list, VISAStatus + """ + raise NotImplementedError + + def move_in_64(self, session, space, offset, length, extended=False): + """Moves an 64-bit block of data from the specified address space and offset to local memory. + + Corresponds to viMoveIn64* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param extended: Use 64 bits offset independent of the platform. + :return: Data read from the bus, return value of the library call. + :rtype: list, VISAStatus + """ + raise NotImplementedError + + def move_out(self, session, space, offset, length, data, width, extended=False): + """Moves a block of data from local memory to the specified address space and offset. + + Corresponds to viMoveOut* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param data: Data to write to bus. + :param width: Number of bits to read per element. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def move_out_8(self, session, space, offset, length, data, extended=False): + """Moves an 8-bit block of data from local memory to the specified address space and offset. + + Corresponds to viMoveOut8* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param data: Data to write to bus. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + + Corresponds to viMoveOut8 function of the VISA library. + """ + raise NotImplementedError + + def move_out_16(self, session, space, offset, length, data, extended=False): + """Moves an 16-bit block of data from local memory to the specified address space and offset. + + Corresponds to viMoveOut16* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param data: Data to write to bus. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def move_out_32(self, session, space, offset, length, data, extended=False): + """Moves an 32-bit block of data from local memory to the specified address space and offset. + + Corresponds to viMoveOut32* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param data: Data to write to bus. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def move_out_64(self, session, space, offset, length, data, extended=False): + """Moves an 64-bit block of data from local memory to the specified address space and offset. + + Corresponds to viMoveOut64* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param length: Number of elements to transfer, where the data width of the elements to transfer + is identical to the source data width. + :param data: Data to write to bus. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def open(self, session, resource_name, + access_mode=constants.AccessModes.no_lock, open_timeout=constants.VI_TMO_IMMEDIATE): + """Opens a session to the specified resource. + + Corresponds to viOpen function of the VISA library. + + :param session: Resource Manager session (should always be a session returned from open_default_resource_manager()). + :param resource_name: Unique symbolic name of a resource. + :param access_mode: Specifies the mode by which the resource is to be accessed. (Constants.NULL or Constants.*LOCK*) + :param open_timeout: Specifies the maximum time period (in milliseconds) that this operation waits + before returning an error. + :return: Unique logical identifier reference to a session, return value of the library call. + :rtype: session, VISAStatus + """ + raise NotImplementedError + + def open_default_resource_manager(self): + """This function returns a session to the Default Resource Manager resource. + + Corresponds to viOpenDefaultRM function of the VISA library. + + :return: Unique logical identifier to a Default Resource Manager session, return value of the library call. + :rtype: session, VISAStatus + """ + raise NotImplementedError + + def out_8(self, session, space, offset, data, extended=False): + """Write in an 8-bit value from the specified memory space and offset. + + Corresponds to viOut8* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param data: Data to write to bus. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def out_16(self, session, space, offset, data, extended=False): + """Write in an 16-bit value from the specified memory space and offset. + + Corresponds to viOut16* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param data: Data to write to bus. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def out_32(self, session, space, offset, data, extended=False): + """Write in an 32-bit value from the specified memory space and offset. + + Corresponds to viOut32* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param data: Data to write to bus. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def out_64(self, session, space, offset, data, extended=False): + """Write in an 64-bit value from the specified memory space and offset. + + Corresponds to viOut64* functions of the VISA library. + + :param session: Unique logical identifier to a session. + :param space: Specifies the address space. (Constants.*SPACE*) + :param offset: Offset (in bytes) of the address or register from which to read. + :param data: Data to write to bus. + :param extended: Use 64 bits offset independent of the platform. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def parse_resource(self, session, resource_name): + """Parse a resource string to get the interface information. + + Corresponds to viParseRsrc function of the VISA library. + + :param session: Resource Manager session (should always be the Default Resource Manager for VISA + returned from open_default_resource_manager()). + :param resource_name: Unique symbolic name of a resource. + :return: Resource information with interface type and board number, return value of the library call. + :rtype: :class:ResourceInfo, VISAStatus + """ + raise NotImplementedError + + def parse_resource_extended(self, session, resource_name): + """Parse a resource string to get extended interface information. + + Corresponds to viParseRsrcEx function of the VISA library. + + :param session: Resource Manager session (should always be the Default Resource Manager for VISA + returned from open_default_resource_manager()). + :param resource_name: Unique symbolic name of a resource. + :return: Resource information, return value of the library call. + :rtype: :class:ResourceInfo, VISAStatus + """ + raise NotImplementedError + + def peek_8(self, session, address): + """Read an 8-bit value from the specified address. + + Corresponds to viPeek8 function of the VISA library. + + :param session: Unique logical identifier to a session. + :param address: Source address to read the value. + :return: Data read from bus, return value of the library call. + :rtype: bytes, VISAStatus + """ + raise NotImplementedError + + def peek_16(self, session, address): + """Read an 16-bit value from the specified address. + + Corresponds to viPeek16 function of the VISA library. + + :param session: Unique logical identifier to a session. + :param address: Source address to read the value. + :return: Data read from bus, return value of the library call. + :rtype: bytes, VISAStatus + """ + raise NotImplementedError + + def peek_32(self, session, address): + """Read an 32-bit value from the specified address. + + Corresponds to viPeek32 function of the VISA library. + + :param session: Unique logical identifier to a session. + :param address: Source address to read the value. + :return: Data read from bus, return value of the library call. + :rtype: bytes, VISAStatus + """ + raise NotImplementedError + + def peek_64(self, session, address): + """Read an 64-bit value from the specified address. + + Corresponds to viPeek64 function of the VISA library. + + :param session: Unique logical identifier to a session. + :param address: Source address to read the value. + :return: Data read from bus, return value of the library call. + :rtype: bytes, VISAStatus + """ + raise NotImplementedError + + def poke_8(self, session, address, data): + """Write an 8-bit value from the specified address. + + Corresponds to viPoke8 function of the VISA library. + + :param session: Unique logical identifier to a session. + :param address: Source address to read the value. + :param data: value to be written to the bus. + :return: Data read from bus. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def poke_16(self, session, address, data): + """Write an 16-bit value from the specified address. + + Corresponds to viPoke16 function of the VISA library. + + :param session: Unique logical identifier to a session. + :param address: Source address to read the value. + :param data: value to be written to the bus. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def poke_32(self, session, address, data): + """Write an 32-bit value from the specified address. + + Corresponds to viPoke32 function of the VISA library. + + :param session: Unique logical identifier to a session. + :param address: Source address to read the value. + :param data: value to be written to the bus. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def poke_64(self, session, address, data): + """Write an 64-bit value from the specified address. + + Corresponds to viPoke64 function of the VISA library. + + :param session: Unique logical identifier to a session. + :param address: Source address to read the value. + :param data: value to be written to the bus. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + 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 + """ + raise NotImplementedError + + def read_asynchronously(self, session, count): + """Reads data from device or interface asynchronously. + + Corresponds to viReadAsync function of the VISA library. + + :param session: Unique logical identifier to a session. + :param count: Number of bytes to be read. + :return: result, jobid, return value of the library call. + :rtype: ctypes buffer, jobid, VISAStatus + """ + raise NotImplementedError + + def read_stb(self, session): + """Reads a status byte of the service request. + + Corresponds to viReadSTB function of the VISA library. + + :param session: Unique logical identifier to a session. + :return: Service request status byte, return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + + def read_to_file(self, session, filename, count): + """Read data synchronously, and store the transferred data in a file. + + Corresponds to viReadToFile function of the VISA library. + + :param session: Unique logical identifier to a session. + :param filename: Name of file to which data will be written. + :param count: Number of bytes to be read. + :return: Number of bytes actually transferred, return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + + def set_attribute(self, session, attribute, attribute_state): + """Sets the state of an attribute. + + Corresponds to viSetAttribute function of the VISA library. + + :param session: Unique logical identifier to a session. + :param attribute: Attribute for which the state is to be modified. (Attributes.*) + :param attribute_state: The state of the attribute to be set for the specified object. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def set_buffer(self, session, mask, size): + """Sets the size for the formatted I/O and/or low-level I/O communication buffer(s). + + Corresponds to viSetBuf function of the VISA library. + + :param session: Unique logical identifier to a session. + :param mask: Specifies the type of buffer. (Constants.READ_BUF, .WRITE_BUF, .IO_IN_BUF, .IO_OUT_BUF) + :param size: The size to be set for the specified buffer(s). + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def status_description(self, session, status): + """Returns a user-readable description of the status code passed to the operation. + + Corresponds to viStatusDesc function of the VISA library. + + :param session: Unique logical identifier to a session. + :param status: Status code to interpret. + :return: - The user-readable string interpretation of the status code passed to the operation, + - return value of the library call. + :rtype: - unicode (Py2) or str (Py3) + - VISAStatus + """ + raise NotImplementedError + + def terminate(self, session, degree, job_id): + """Requests a VISA session to terminate normal execution of an operation. + + Corresponds to viTerminate function of the VISA library. + + :param session: Unique logical identifier to a session. + :param degree: Constants.NULL + :param job_id: Specifies an operation identifier. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def uninstall_handler(self, session, event_type, handler, user_handle=None): + """Uninstalls handlers for events. + + Corresponds to viUninstallHandler function of the VISA library. + + :param session: Unique logical identifier to a session. + :param event_type: Logical event identifier. + :param handler: Interpreted as a valid reference to a handler to be uninstalled by a client application. + :param user_handle: A value specified by an application that can be used for identifying handlers + uniquely in a session for an event. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def unlock(self, session): + """Relinquishes a lock for the specified resource. + + Corresponds to viUnlock function of the VISA library. + + :param session: Unique logical identifier to a session. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def unmap_address(self, session): + """Unmaps memory space previously mapped by map_address(). + + Corresponds to viUnmapAddress function of the VISA library. + + :param session: Unique logical identifier to a session. + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def unmap_trigger(self, session, trigger_source, trigger_destination): + """Undo a previous map from the specified trigger source line to the specified destination line. + + Corresponds to viUnmapTrigger function of the VISA library. + + :param session: Unique logical identifier to a session. + :param trigger_source: Source line used in previous map. (Constants.TRIG*) + :param trigger_destination: Destination line used in previous map. (Constants.TRIG*) + :return: return value of the library call. + :rtype: VISAStatus + """ + raise NotImplementedError + + def usb_control_in(self, session, request_type_bitmap_field, request_id, request_value, + index, length=0): + """Performs a USB control pipe transfer from the device. + + Corresponds to viUsbControlIn function of the VISA library. + + :param session: Unique logical identifier to a session. + :param request_type_bitmap_field: bmRequestType parameter of the setup stage of a USB control transfer. + :param request_id: bRequest parameter of the setup stage of a USB control transfer. + :param request_value: wValue parameter of the setup stage of a USB control transfer. + :param index: wIndex parameter of the setup stage of a USB control transfer. + This is usually the index of the interface or endpoint. + :param length: wLength parameter of the setup stage of a USB control transfer. + This value also specifies the size of the data buffer to receive the data from the + optional data stage of the control transfer. + :return: - The data buffer that receives the data from the optional data stage of the control transfer + - return value of the library call. + :rtype: - bytes + - VISAStatus + """ + raise NotImplementedError + + def usb_control_out(self, session, request_type_bitmap_field, request_id, request_value, + index, data=""): + """Performs a USB control pipe transfer to the device. + + Corresponds to viUsbControlOut function of the VISA library. + + :param session: Unique logical identifier to a session. + :param request_type_bitmap_field: bmRequestType parameter of the setup stage of a USB control transfer. + :param request_id: bRequest parameter of the setup stage of a USB control transfer. + :param request_value: wValue parameter of the setup stage of a USB control transfer. + :param index: wIndex parameter of the setup stage of a USB control transfer. + This is usually the index of the interface or endpoint. + :param data: The data buffer that sends the data in the optional data stage of the control transfer. + :return: return value of the library call. + :rtype: VISAStatus + """ + + def vxi_command_query(self, session, mode, command): + """Sends the device a miscellaneous command or query and/or retrieves the response to a previous query. + + Corresponds to viVxiCommandQuery function of the VISA library. + + :param session: Unique logical identifier to a session. + :param mode: Specifies whether to issue a command and/or retrieve a response. (Constants.VXI_CMD*, .VXI_RESP*) + :param command: The miscellaneous command to send. + :return: The response retrieved from the device, return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + + def wait_on_event(self, session, in_event_type, timeout): + """Waits for an occurrence of the specified event for a given session. + + Corresponds to viWaitOnEvent function of the VISA library. + + :param session: Unique logical identifier to a session. + :param in_event_type: Logical identifier of the event(s) to wait for. + :param timeout: 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. + :return: - Logical identifier of the event actually received + - A handle specifying the unique occurrence of an event + - return value of the library call. + :rtype: - eventtype + - event + - VISAStatus + """ + raise NotImplementedError + + 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 + """ + raise NotImplementedError + + def write_asynchronously(self, session, data): + """Writes data to device or interface asynchronously. + + Corresponds to viWriteAsync function of the VISA library. + + :param session: Unique logical identifier to a session. + :param data: data to be written. + :return: Job ID of this asynchronous write operation, return value of the library call. + :rtype: jobid, VISAStatus + """ + raise NotImplementedError + + def write_from_file(self, session, filename, count): + """Take data from a file and write it out synchronously. + + Corresponds to viWriteFromFile function of the VISA library. + + :param session: Unique logical identifier to a session. + :param filename: Name of file from which data will be read. + :param count: Number of bytes to be written. + :return: Number of bytes actually transferred, return value of the library call. + :rtype: int, VISAStatus + """ + raise NotImplementedError + +def list_wrappers(): + return [name for (loader, name, ispkg) in pkgutil.iter_modules() + if name.startswith('pyvisa-')] + +_WRAPPERS = {} +def get_wrapper(wrapper_name): + try: + return _WRAPPERS[wrapper_name] + except KeyError: + if wrapper_name == 'ni': + from .ctwrapper import NIVisaLibrary + _WRAPPERS['ni'] = NIVisaLibrary + return NIVisaLibrary + + for pkgname in list_wrappers(): + if pkgname.endswith('-' + wrapper_name): + pkg = __import__(pkgname) + _WRAPPERS[wrapper_name] = cls = pkg.WRAPPER_CLASS + return cls + else: + raise ValueError('No package named pyvisa-%s' % wrapper_name) + + +def open_visa_library(*paths): + """Helper function to create a VISA library wrapper. + + In general, you should not use the function directly. The VISA library + wrapper will be created automatically when you create a ResourceManager object. + + The function takes + """ + if not paths: + return open_visa_library(*util.get_library_paths()) + + errs = [] + for path in paths: + try: + path, wrapper = path.split('@') + except ValueError: + wrapper = 'ni' + + if not path: + return open_visa_library(*util.get_library_paths()) + + cls = get_wrapper(wrapper) + try: + return cls(path) + except OSError as e: + logger.debug('Could not open VISA library %s: %s', path, str(e)) + errs.append(str(e)) + except Exception as e: + errs.append(str(e)) + else: + raise OSError('Could not open VISA library:\n' + '\n'.join(errs)) class ResourceManager(object): @@ -288,9 +1424,13 @@ class ResourceManager(object): #: Session handler for the resource manager. _session = None - def __new__(cls, visa_library=None): - if visa_library is None or isinstance(visa_library, str): - visa_library = VisaLibrary(visa_library) + def __new__(cls, visa_library=()): + if isinstance(visa_library, str): + visa_library = open_visa_library(*(visa_library,)) + elif visa_library is None: + visa_library = open_visa_library() + else: + visa_library = open_visa_library(*visa_library) if visa_library in cls._registry: return cls._registry[visa_library] @@ -331,6 +1471,7 @@ class ResourceManager(object): logger.debug('Closing ResourceManager (session: %s)', self.session) self.visalib.close(self.session) self.session = None + del self._registry[self.visalib] except errors.InvalidSession: pass @@ -16,7 +16,7 @@ from __future__ import division, unicode_literals, print_function, absolute_import from pyvisa import logger, __version__, log_to_screen -from pyvisa.highlevel import VisaLibrary, ResourceManager +from pyvisa.highlevel import ResourceManager from pyvisa.errors import (Error, VisaIOError, VisaIOWarning, VisaTypeError, UnknownHandler, OSNotSupported, InvalidBinaryFormat) from pyvisa.resources import Resource |