Source code for pyvisa.highlevel

# -*- coding: utf-8 -*-
"""High level Visa library wrapper.

This file is part of PyVISA.

:copyright: 2014-2022 by PyVISA Authors, see AUTHORS for more details.
:license: MIT, see LICENSE for more details.

"""
import atexit
import contextlib
import copy
import os
import pkgutil
import warnings
from collections import defaultdict
from importlib import import_module
from itertools import chain
from types import ModuleType
from typing import (
    TYPE_CHECKING,
    Any,
    Callable,
    ContextManager,
    Dict,
    Iterable,
    Iterator,
    List,
    NamedTuple,
    Optional,
    Set,
    SupportsBytes,
    Tuple,
    Type,
    TypeVar,
    Union,
    cast,
)
from weakref import WeakMethod, WeakSet, WeakValueDictionary

from typing_extensions import ClassVar, DefaultDict, Literal

from . import attributes, constants, errors, logger, rname
from .constants import StatusCode
from .typing import (
    VISAEventContext,
    VISAHandler,
    VISAJobID,
    VISAMemoryAddress,
    VISARMSession,
    VISASession,
)
from .util import DebugInfo, LibraryPath

if TYPE_CHECKING:
    from .resources import Resource  # pragma: no cover

#: Resource extended information
#:
#: Named tuple with information about a resource. Returned by some :class:`ResourceManager` methods.
#:
#: :interface_type: Interface type of the given resource string. :class:`pyvisa.constants.InterfaceType`
#: :interface_board_number: Board number of the interface of the given resource string. We allow None
#:                          since serial resources may not sometimes be easily described
#:                          by a single number in particular on Linux system.
#: :resource_class: Specifies the resource class (for example, "INSTR") of the given resource string.
#: :resource_name: This is the expanded version of the given resource string.
#:                 The format should be similar to the VISA-defined canonical resource name.
#: :alias: Specifies the user-defined alias for the given resource string.
ResourceInfo = NamedTuple(
    "ResourceInfo",
    (
        ("interface_type", constants.InterfaceType),
        ("interface_board_number", Optional[int]),
        ("resource_class", Optional[str]),
        ("resource_name", Optional[str]),
        ("alias", Optional[str]),
    ),
)

# Used to properly type the __new__ method
T = TypeVar("T", bound="VisaLibraryBase")


[docs]class VisaLibraryBase(object): """Base for VISA library classes. A class derived from `VisaLibraryBase` library provides the low-level communication to the underlying devices providing Pythonic wrappers to VISA functions. But not all derived class must/will implement all methods. Even if methods are expected to return the status code they are expected to raise the appropriate exception when an error occurred since this is more Pythonic. The default VisaLibrary class is :class:`pyvisa.ctwrapper.highlevel.IVIVisaLibrary`, which implements a ctypes wrapper around the IVI-VISA library. Certainly, IVI-VISA can be NI-VISA, Keysight VISA, R&S VISA, tekVISA etc. In general, you should not instantiate it directly. The object exposed to the user is the :class:`pyvisa.highlevel.ResourceManager`. If needed, you can access the VISA library from it:: >>> import pyvisa >>> rm = pyvisa.ResourceManager("/path/to/my/libvisa.so.7") >>> lib = rm.visalib """ #: Default ResourceManager instance for this library. resource_manager: Optional["ResourceManager"] #: Path to the VISA library used by this instance library_path: LibraryPath #: Maps library path to VisaLibrary object _registry: ClassVar[ Dict[Tuple[Type["VisaLibraryBase"], LibraryPath], "VisaLibraryBase"] ] = WeakValueDictionary() # type: ignore #: Last return value of the library. _last_status: StatusCode = StatusCode(0) #: Maps session handle to last status. _last_status_in_session: Dict[ Union[VISASession, VISARMSession, VISAEventContext], StatusCode ] #: Maps session handle to warnings to ignore. _ignore_warning_in_session: Dict[int, set] #: Extra information used for logging errors _logging_extra: Dict[str, str] #: Contains all installed event handlers. #: Its elements are tuples with four elements: The handler itself (a Python #: callable), the user handle (in any format making sense to the lower level #: implementation, ie as a ctypes object for the ctypes backend) and the #: handler again, this time in a format meaningful to the backend (ie as a #: ctypes object created with CFUNCTYPE for the ctypes backend) and #: the event type. handlers: DefaultDict[VISASession, List[Tuple[VISAHandler, Any, Any, Any]]] #: Set error codes on which to issue a warning. issue_warning_on: Set[StatusCode] def __new__( cls: Type[T], library_path: Union[str, LibraryPath] = "" ) -> "VisaLibraryBase": """Create a new VISA library from the specified path. If a library was already created using the same path and class this library object is returned instead. Parameters ---------- library_path : str | LibraryPath Path to the VISA library to use in the backend. Raises ------ OSError Raised if the VISA library object could not be created. """ if library_path == "": errs = [] for path in cls.get_library_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)) except Exception as e: errs.append(str(e)) else: raise OSError("Could not open VISA library:\n" + "\n".join(errs)) if not isinstance(library_path, LibraryPath): lib_path = LibraryPath(library_path, "user specified") else: lib_path = library_path if (cls, lib_path) in cls._registry: return cls._registry[(cls, lib_path)] obj = super(VisaLibraryBase, cls).__new__(cls) obj.library_path = lib_path obj._logging_extra = {"library_path": obj.library_path} obj._init() # Create instance specific registries. #: Error codes on which to issue a warning. obj.issue_warning_on = set(errors.default_warnings) obj._last_status_in_session = dict() obj._ignore_warning_in_session = defaultdict(set) obj.handlers = defaultdict(list) obj.resource_manager = None logger.debug("Created library wrapper for %s", lib_path) cls._registry[(cls, lib_path)] = obj return obj
[docs] @staticmethod def get_library_paths() -> Iterable[LibraryPath]: """Override to list the possible library_paths if no path is specified.""" return ()
[docs] @staticmethod def get_debug_info() -> DebugInfo: """Override to return an iterable of lines with the backend debug details.""" return ["Does not provide debug info"]
def _init(self) -> None: """Override this method to customize VisaLibrary initialization.""" pass def __str__(self) -> str: """str representation of the library.""" return "Visa Library at %s" % self.library_path def __repr__(self) -> str: """str representation of the library including the type of the library.""" return "<%s(%r)>" % (type(self).__name__, self.library_path)
[docs] def handle_return_value( self, session: Optional[Union[VISAEventContext, VISARMSession, VISASession]], status_code: int, ) -> StatusCode: """Helper function handling the return code of a low-level operation. Used when implementing concrete subclasses of VISALibraryBase. """ rv: StatusCode try: rv = StatusCode(status_code) except ValueError: rv = cast(StatusCode, status_code) self._last_status = rv if session is not None: self._last_status_in_session[session] = rv if rv < 0: raise errors.VisaIOError(rv) if rv in self.issue_warning_on: if session and rv not in self._ignore_warning_in_session[session]: warnings.warn(errors.VisaIOWarning(rv), stacklevel=2) # Return the original value for further processing. return rv
@property def last_status(self) -> StatusCode: """Last return value of the library.""" return self._last_status
[docs] def get_last_status_in_session( self, session: Union[VISASession, VISARMSession] ) -> StatusCode: """Last status in session. Helper function to be called by resources properties. """ try: return self._last_status_in_session[session] except KeyError: raise errors.Error( "The session %r does not seem to be valid as it does not have any last status" % session )
[docs] @contextlib.contextmanager def ignore_warning( self, session: Union[VISASession, VISARMSession], *warnings_constants: StatusCode, ) -> Iterator: """Ignore warnings for a session for the duration of the context. Parameters ---------- session : Union[VISASession, VISARMSession] Unique logical identifier to a session. warnings_constants : StatusCode Constants identifying the warnings to ignore. """ self._ignore_warning_in_session[session].update(warnings_constants) yield self._ignore_warning_in_session[session].difference_update(warnings_constants)
[docs] def install_visa_handler( self, session: VISASession, event_type: constants.EventType, handler: VISAHandler, user_handle: Any = None, ) -> Any: """Installs handlers for event callbacks. Parameters ---------- session : VISASession Unique logical identifier to a session. event_type : constants.EventType, Logical event identifier. handler : VISAHandler Handler to be installed by a client application. user_handle : A value specified by an application that can be used for identifying handlers uniquely for an event type. Returns ------- converted_user_handle: Converted user handle to match the underlying library. This version of the handle should be used in further call to the library. """ try: new_handler = self.install_handler( session, event_type, handler, user_handle ) except TypeError as e: raise errors.VisaTypeError(str(e)) from e self.handlers[session].append(new_handler[:-1] + (event_type,)) return new_handler[1]
[docs] def uninstall_visa_handler( self, session: VISASession, event_type: constants.EventType, handler: VISAHandler, user_handle: Any = None, ) -> None: """Uninstalls handlers for events. Parameters ---------- session : VISASession Unique logical identifier to a session. event_type : constants.EventType Logical event identifier. handler : VISAHandler Handler to be uninstalled by a client application. user_handle : The user handle returned by install_visa_handler. """ for ndx, element in enumerate(self.handlers[session]): # use == rather than is to allow bound methods as handlers if ( element[0] == handler and element[1] is user_handle and element[3] == event_type ): del self.handlers[session][ndx] break else: raise errors.UnknownHandler(event_type, handler, user_handle) self.uninstall_handler(session, event_type, element[2], user_handle)
def __uninstall_all_handlers_helper(self, session: VISASession) -> None: """Uninstall all VISA handlers for a given session.""" for element in self.handlers[session]: self.uninstall_handler(session, element[3], element[2], element[1]) del self.handlers[session]
[docs] def uninstall_all_visa_handlers(self, session: Optional[VISASession]) -> None: """Uninstalls all previously installed handlers for a particular session. Parameters ---------- session : VISASession | None Unique logical identifier to a session. If None, operates on all sessions. """ if session is not None: self.__uninstall_all_handlers_helper(session) else: for session in list(self.handlers): self.__uninstall_all_handlers_helper(session)
[docs] def read_memory( self, session: VISASession, space: constants.AddressSpace, offset: int, width: Union[Literal[8, 16, 32, 64], constants.DataWidth], extended: bool = False, ) -> Tuple[int, StatusCode]: """Read a value from the specified memory space and offset. Corresponds to viIn* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Specifies the address space from which to read. offset : int Offset (in bytes) of the address or register from which to read. width : Union[Literal[8, 16, 32, 64], constants.DataWidth] Number of bits to read (8, 16, 32 or 64). extended : bool, optional Use 64 bits offset independent of the platform. Returns ------- data : int Data read from memory status_code : StatusCode Return value of the library call. Raises ------ ValueError Raised if an invalid width is specified. """ w = width * 8 if isinstance(width, constants.DataWidth) else width if w not in (8, 16, 32, 64): raise ValueError( "%s is not a valid size. Valid values are 8, 16, 32 or 64 " "or one member of constants.DataWidth" % width ) return getattr(self, f"in_{w}")(session, space, offset, extended)
[docs] def write_memory( self, session: VISASession, space: constants.AddressSpace, offset: int, data: int, width: Union[Literal[8, 16, 32, 64], constants.DataWidth], extended: bool = False, ) -> StatusCode: """Write a value to the specified memory space and offset. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Specifies the address space. offset : int Offset (in bytes) of the address or register from which to read. data : int Data to write to bus. width : Union[Literal[8, 16, 32, 64], constants.DataWidth] Number of bits to read. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- StatusCode Return value of the library call. Raises ------ ValueError Raised if an invalid width is specified. """ w = width * 8 if isinstance(width, constants.DataWidth) else width if w not in (8, 16, 32, 64): raise ValueError( "%s is not a valid size. Valid values are 8, 16, 32 or 64 " "or one member of constants.DataWidth" % width ) return getattr(self, f"out_{w}")(session, space, offset, data, extended)
[docs] def move_in( self, session: VISASession, space: constants.AddressSpace, offset: int, length: int, width: Union[Literal[8, 16, 32, 64], constants.DataWidth], extended: bool = False, ) -> Tuple[List[int], StatusCode]: """Move a block of data to local memory from the given address space and offset. Corresponds to viMoveIn* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space from which to move the data. offset : int Offset (in bytes) of the address or register from which to read. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. width : Union[Literal[8, 16, 32, 64], constants.DataWidth] Number of bits to read per element. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- data : List[int] Data read from the bus status_code : StatusCode Return value of the library call. Raises ------ ValueError Raised if an invalid width is specified. """ w = width * 8 if isinstance(width, constants.DataWidth) else width if w not in (8, 16, 32, 64): raise ValueError( "%s is not a valid size. Valid values are 8, 16, 32 or 64 " "or one member of constants.DataWidth" % width ) return getattr(self, f"move_in_{w}")(session, space, offset, length, extended)
[docs] def move_out( self, session: VISASession, space: constants.AddressSpace, offset: int, length: int, data: Iterable[int], width: Union[Literal[8, 16, 32, 64], constants.DataWidth], extended: bool = False, ) -> StatusCode: """Move a block of data from local memory to the given address space and offset. Corresponds to viMoveOut* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space into which move the data. offset : int Offset (in bytes) of the address or register from which to read. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. data : Iterable[int] Data to write to bus. width : Union[Literal[8, 16, 32, 64], constants.DataWidth] Number of bits to per element. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- StatusCode Return value of the library call. Raises ------ ValueError Raised if an invalid width is specified. """ w = width * 8 if isinstance(width, constants.DataWidth) else width if w not in (8, 16, 32, 64): raise ValueError( "%s is not a valid size. Valid values are 8, 16, 32 or 64 " "or one member of constants.DataWidth" % width ) return getattr(self, f"move_out_{w}")( session, space, offset, length, data, extended )
[docs] def peek( self, session: VISASession, address: VISAMemoryAddress, width: Union[Literal[8, 16, 32, 64], constants.DataWidth], ) -> Tuple[int, StatusCode]: """Read an 8, 16, 32, or 64-bit value from the specified address. Corresponds to viPeek* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. width : Union[Literal[8, 16, 32, 64], constants.DataWidth] Number of bits to read. Returns ------- data : int Data read from bus status_code : StatusCode Return value of the library call. Raises ------ ValueError Raised if an invalid width is specified. """ w = width * 8 if isinstance(width, constants.DataWidth) else width if w not in (8, 16, 32, 64): raise ValueError( "%s is not a valid size. Valid values are 8, 16, 32 or 64 " "or one member of constants.DataWidth" % width ) return getattr(self, f"peek_{w}")(session, address)
[docs] def poke( self, session: VISASession, address: VISAMemoryAddress, width: Union[Literal[8, 16, 32, 64], constants.DataWidth], data: int, ) -> StatusCode: """Writes an 8, 16, 32, or 64-bit value from the specified address. Corresponds to viPoke* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. width : Union[Literal[8, 16, 32, 64], constants.DataWidth] Number of bits to read. data : int Data to write to the bus Returns ------- status_code : StatusCode Return value of the library call. Raises ------ ValueError Raised if an invalid width is specified. """ w = width * 8 if isinstance(width, constants.DataWidth) else width if w not in (8, 16, 32, 64): raise ValueError( "%s is not a valid size. Valid values are 8, 16, 32 or 64 " "or one member of constants.DataWidth" % width ) return getattr(self, f"poke_{w}")(session, address, data)
# Methods that VISA Library implementations must implement
[docs] def assert_interrupt_signal( self, session: VISASession, mode: constants.AssertSignalInterrupt, status_id: int, ) -> StatusCode: """Asserts the specified interrupt or signal. Corresponds to viAssertIntrSignal function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. mode : constants.AssertSignalInterrupt How to assert the interrupt. status_id : int Status value to be presented during an interrupt acknowledge cycle. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def assert_trigger( self, session: VISASession, protocol: constants.TriggerProtocol ) -> StatusCode: """Assert software or hardware trigger. Corresponds to viAssertTrigger function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. protocol : constants.TriggerProtocol Trigger protocol to use during assertion. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def assert_utility_signal( self, session: VISASession, line: constants.UtilityBusSignal ) -> StatusCode: """Assert or deassert the specified utility bus signal. Corresponds to viAssertUtilSignal function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. line : constants.UtilityBusSignal Specifies the utility bus signal to assert. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def buffer_read(self, session: VISASession, count: int) -> Tuple[bytes, StatusCode]: """Reads data through the use of a formatted I/O read buffer. The data can be read from a device or an interface. Corresponds to viBufRead function of the VISA library. Parameters ---------- session : VISASession\ Unique logical identifier to a session. count : int Number of bytes to be read. Returns ------- dbytes Data read StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def buffer_write(self, session: VISASession, data: bytes) -> Tuple[int, StatusCode]: """Writes data to a formatted I/O write buffer synchronously. Corresponds to viBufWrite function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. data : bytes Data to be written. Returns ------- int number of written bytes StatusCode return value of the library call. """ raise NotImplementedError
[docs] def clear(self, session: VISASession) -> StatusCode: """Clears a device. Corresponds to viClear function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def close( self, session: Union[VISASession, VISAEventContext, VISARMSession] ) -> StatusCode: """Closes the specified session, event, or find list. Corresponds to viClose function of the VISA library. Parameters --------- session : Union[VISASession, VISAEventContext, VISARMSession] Unique logical identifier to a session, event, resource manager. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def disable_event( self, session: VISASession, event_type: constants.EventType, mechanism: constants.EventMechanism, ) -> StatusCode: """Disable notification for an event type(s) via the specified mechanism(s). Corresponds to viDisableEvent function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. event_type : constants.EventType Event type. mechanism : constants.EventMechanism Event handling mechanisms to be disabled. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def discard_events( self, session: VISASession, event_type: constants.EventType, mechanism: constants.EventMechanism, ) -> StatusCode: """Discard event occurrences for a given type and mechanisms in a session. Corresponds to viDiscardEvents function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. event_type : constants.EventType Logical event identifier. mechanism : constants.EventMechanism Specifies event handling mechanisms to be discarded. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def enable_event( self, session: VISASession, event_type: constants.EventType, mechanism: constants.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 : constants.EventType Logical event identifier. mechanism : constants.EventMechanism Specifies event handling mechanisms to be enabled. context : None, optional Unused parameter... Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def flush( self, session: VISASession, mask: constants.BufferOperation ) -> StatusCode: """Flush the specified buffers. The buffers can be associated with formatted I/O operations and/or serial communication. Corresponds to viFlush function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. mask : constants.BufferOperation Specifies the action to be taken with flushing the buffer. The values can be combined using the | operator. However multiple operations on a single buffer cannot be combined. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def get_attribute( self, session: Union[VISASession, VISAEventContext, VISARMSession], attribute: Union[constants.ResourceAttribute, constants.EventAttribute], ) -> Tuple[Any, StatusCode]: """Retrieves the state of an attribute. Corresponds to viGetAttribute function of the VISA library. Parameters ---------- session : Union[VISASession, VISAEventContext] Unique logical identifier to a session, event, or find list. attribute : Union[constants.ResourceAttribute, constants.EventAttribute] Resource or event attribute for which the state query is made. Returns ------- Any State of the queried attribute for a specified resource StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def gpib_command(self, session: VISASession, data: bytes) -> Tuple[int, StatusCode]: """Write GPIB command bytes on the bus. Corresponds to viGpibCommand function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. data : bytes Data to write. Returns ------- int Number of written bytes StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def gpib_control_atn( self, session: VISASession, mode: constants.ATNLineOperation ) -> StatusCode: """Specifies the state of the ATN line and the local active controller state. Corresponds to viGpibControlATN function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. mode : constants.ATNLineOperation State of the ATN line and optionally the local active controller state. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def gpib_control_ren( self, session: VISASession, mode: constants.RENLineOperation ) -> StatusCode: """Controls the state of the GPIB Remote Enable (REN) interface line. Optionally the remote/local state of the device can also be set. Corresponds to viGpibControlREN function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. mode : constants.RENLineOperation State of the REN line and optionally the device remote/local state. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def gpib_pass_control( self, session: VISASession, primary_address: int, secondary_address: int ) -> StatusCode: """Tell a GPIB device to become controller in charge (CIC). Corresponds to viGpibPassControl function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. primary_address : int Primary address of the GPIB device to which you want to pass control. secondary_address : int Secondary address of the targeted GPIB device. If the targeted device does not have a secondary address, this parameter should contain the value Constants.VI_NO_SEC_ADDR. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def gpib_send_ifc(self, session: VISASession) -> StatusCode: """Pulse the interface clear line (IFC) for at least 100 microseconds. Corresponds to viGpibSendIFC function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def in_8( self, session: VISASession, space: constants.AddressSpace, offset: int, extended: bool = False, ) -> Tuple[int, StatusCode]: """Reads in an 8-bit value from the specified memory space and offset. Corresponds to viIn8* function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Specifies the address space. offset : int Offset (in bytes) of the address or register from which to read. extended : bool, optional Use 64 bits offset independent of the platform, False by default. Returns ------- int Data read from memory StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def in_16( self, session: VISASession, space: constants.AddressSpace, offset: int, extended: bool = False, ) -> Tuple[int, StatusCode]: """Reads in an 16-bit value from the specified memory space and offset. Corresponds to viIn16* function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Specifies the address space. offset : int Offset (in bytes) of the address or register from which to read. extended : bool, optional Use 64 bits offset independent of the platform, False by default. Returns ------- int Data read from memory StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def in_32( self, session: VISASession, space: constants.AddressSpace, offset: int, extended: bool = False, ) -> Tuple[int, StatusCode]: """Reads in an 32-bit value from the specified memory space and offset. Corresponds to viIn32* function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Specifies the address space. offset : int Offset (in bytes) of the address or register from which to read. extended : bool, optional Use 64 bits offset independent of the platform, False by default. Returns ------- int Data read from memory StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def in_64( self, session: VISASession, space: constants.AddressSpace, offset: int, extended: bool = False, ) -> Tuple[int, StatusCode]: """Reads in an 64-bit value from the specified memory space and offset. Corresponds to viIn64* function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Specifies the address space. offset : int Offset (in bytes) of the address or register from which to read. extended : bool, optional Use 64 bits offset independent of the platform, False by default. Returns ------- int Data read from memory StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def install_handler( self, session: VISASession, event_type: constants.EventType, handler: VISAHandler, user_handle: Any, ) -> Tuple[VISAHandler, Any, Any, StatusCode]: """Install handlers for event callbacks. Corresponds to viInstallHandler function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. event_type : constants.EventType Logical event identifier. handler : VISAHandler Reference to a handler to be installed by a client application. user_handle : Any Value specified by an application that can be used for identifying handlers uniquely for an event type. Returns ------- handler : VISAHandler Handler to be installed by a client application. converted_user_handle : Converted user handle to match the underlying library. This version of the handle should be used in further call to the library. converted_handler : Converted version of the handler satisfying to backend library. status_code : StatusCode Return value of the library call """ raise NotImplementedError
[docs] def list_resources( self, session: VISARMSession, query: str = "?*::INSTR" ) -> Tuple[str, ...]: """Return a tuple of all connected devices matching query. Parameters ---------- session : VISARMSession Unique logical identifier to the resource manager session. query : str Regular expression used to match devices. Returns ------- Tuple[str, ...] Resource names of all the connected devices matching the query. """ raise NotImplementedError
[docs] def lock( self, session: VISASession, 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. """ raise NotImplementedError
[docs] def map_address( self, session: VISASession, map_space: constants.AddressSpace, map_base: int, map_size: int, access: Literal[False] = False, suggested: Optional[int] = None, ) -> Tuple[int, StatusCode]: """Maps the specified memory space into the process's address space. Corresponds to viMapAddress function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. map_space : constants.AddressSpace Specifies the address space to map. map_base : int Offset (in bytes) of the memory to be mapped. map_size : int Amount of memory to map (in bytes). access : False Unused parameter. suggested : Optional[int], optional If not None, the operating system attempts to map the memory to the address specified. 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 the suggested one. Returns ------- int Address in your process space where the memory was mapped StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def map_trigger( self, session: VISASession, trigger_source: constants.InputTriggerLine, trigger_destination: constants.OutputTriggerLine, mode: None = None, ) -> StatusCode: """Map the specified trigger source line to the specified destination line. Corresponds to viMapTrigger function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. trigger_source : constants.InputTriggerLine Source line from which to map. trigger_destination : constants.OutputTriggerLine Destination line to which to map. mode : None, optional Always None for this version of the VISA specification. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def memory_allocation( self, session: VISASession, size: int, extended: bool = False ) -> Tuple[int, StatusCode]: """Allocate memory from a resource's memory region. Corresponds to viMemAlloc* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. size : int Specifies the size of the allocation. extended : bool, optional Use 64 bits offset independent of the platform. Returns ------- int offset of the allocated memory StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def memory_free( self, session: VISASession, offset: int, extended: bool = False ) -> StatusCode: """Frees memory previously allocated using the memory_allocation() operation. Corresponds to viMemFree* function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. offset : int Offset of the memory to free. extended : bool, optional Use 64 bits offset independent of the platform. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def move( self, session: VISASession, source_space: constants.AddressSpace, source_offset: int, source_width: constants.DataWidth, destination_space: constants.AddressSpace, destination_offset: int, destination_width: constants.DataWidth, length: int, ) -> StatusCode: """Moves a block of data. Corresponds to viMove function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. source_space : constants.AddressSpace Specifies the address space of the source. source_offset : int Offset of the starting address or register from which to read. source_width : constants.DataWidth Specifies the data width of the source. destination_space : constants.AddressSpace Specifies the address space of the destination. destination_offset : int Offset of the starting address or register to which to write. destination_width : constants.DataWidth Specifies the data width of the destination. length: int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def move_asynchronously( self, session: VISASession, source_space: constants.AddressSpace, source_offset: int, source_width: constants.DataWidth, destination_space: constants.AddressSpace, destination_offset: int, destination_width: constants.DataWidth, length: int, ) -> Tuple[VISAJobID, StatusCode]: """Moves a block of data asynchronously. Corresponds to viMoveAsync function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. source_space : constants.AddressSpace Specifies the address space of the source. source_offset : int Offset of the starting address or register from which to read. source_width : constants.DataWidth Specifies the data width of the source. destination_space : constants.AddressSpace Specifies the address space of the destination. destination_offset : int Offset of the starting address or register to which to write. destination_width : constants.DataWidth Specifies the data width of the destination. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. Returns ------- VISAJobID Job identifier of this asynchronous move operation StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def move_in_8( self, session: VISASession, space: constants.AddressSpace, offset: int, length: int, extended: bool = False, ) -> Tuple[List[int], StatusCode]: """Moves an 8-bit block of data to local memory. Corresponds to viMoveIn8* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space from which to move the data. offset : int Offset (in bytes) of the address or register from which to read. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- data : List[int] Data read from the bus status_code : StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def move_in_16( self, session: VISASession, space: constants.AddressSpace, offset: int, length: int, extended: bool = False, ) -> Tuple[List[int], StatusCode]: """Moves an 16-bit block of data to local memory. Corresponds to viMoveIn816 functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space from which to move the data. offset : int Offset (in bytes) of the address or register from which to read. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- data : List[int] Data read from the bus status_code : StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def move_in_32( self, session: VISASession, space: constants.AddressSpace, offset: int, length: int, extended: bool = False, ) -> Tuple[List]: """Moves an 32-bit block of data to local memory. Corresponds to viMoveIn32* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space from which to move the data. offset : int Offset (in bytes) of the address or register from which to read. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- data : List[int] Data read from the bus status_code : StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def move_in_64( self, session: VISASession, space: constants.AddressSpace, offset: int, length: int, extended: bool = False, ) -> Tuple[List[int], StatusCode]: """Moves an 64-bit block of data to local memory. Corresponds to viMoveIn8* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space from which to move the data. offset : int Offset (in bytes) of the address or register from which to read. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- data : List[int] Data read from the bus status_code : StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def move_out_8( self, session: VISASession, space: constants.AddressSpace, offset: int, length: int, data: Iterable[int], extended: bool = False, ) -> StatusCode: """Moves an 8-bit block of data from local memory. Corresponds to viMoveOut8* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space into which move the data. offset : int Offset (in bytes) of the address or register from which to read. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. data : Iterable[int] Data to write to bus. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def move_out_16( self, session: VISASession, space: constants.AddressSpace, offset: int, length: int, data: Iterable[int], extended: bool = False, ) -> StatusCode: """Moves an 16-bit block of data from local memory. Corresponds to viMoveOut16* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space into which move the data. offset : int Offset (in bytes) of the address or register from which to read. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. data : Iterable[int] Data to write to bus. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def move_out_32( self, session: VISASession, space: constants.AddressSpace, offset: int, length: int, data: Iterable[int], extended: bool = False, ) -> StatusCode: """Moves an 32-bit block of data from local memory. Corresponds to viMoveOut32* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space into which move the data. offset : int Offset (in bytes) of the address or register from which to read. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. data : Iterable[int] Data to write to bus. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def move_out_64( self, session: VISASession, space: constants.AddressSpace, offset: int, length: int, data: Iterable[int], extended: bool = False, ) -> StatusCode: """Moves an 64-bit block of data from local memory. Corresponds to viMoveOut64* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space into which move the data. offset : int Offset (in bytes) of the address or register from which to read. length : int Number of elements to transfer, where the data width of the elements to transfer is identical to the source data width. data : Iterable[int] Data to write to bus. extended : bool, optional Use 64 bits offset independent of the platform, by default False. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def open( self, session: VISARMSession, resource_name: str, access_mode: constants.AccessModes = constants.AccessModes.no_lock, open_timeout: int = constants.VI_TMO_IMMEDIATE, ) -> Tuple[VISASession, StatusCode]: """Opens a session to the specified resource. Corresponds to viOpen function of the VISA library. Parameters ---------- session : VISARMSession Resource Manager session (should always be a session returned from open_default_resource_manager()). resource_name : str Unique symbolic name of a resource. access_mode : constants.AccessModes, optional Specifies the mode by which the resource is to be accessed. open_timeout : int If the ``access_mode`` parameter requests a lock, then this parameter specifies the absolute time period (in milliseconds) that the resource waits to get unlocked before this operation returns an error. Returns ------- VISASession Unique logical identifier reference to a session StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def open_default_resource_manager(self) -> Tuple[VISARMSession, StatusCode]: """This function returns a session to the Default Resource Manager resource. Corresponds to viOpenDefaultRM function of the VISA library. Returns ------- VISARMSession Unique logical identifier to a Default Resource Manager session StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def out_8( self, session: VISASession, space: constants.AddressSpace, offset: int, data: int, extended: bool = False, ) -> StatusCode: """Write an 8-bit value to the specified memory space and offset. Corresponds to viOut8* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space into which to write. offset : int Offset (in bytes) of the address or register from which to read. data : int Data to write to bus. extended : bool, optional Use 64 bits offset independent of the platform. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def out_16( self, session: VISASession, space: constants.AddressSpace, offset: int, data: int, extended: bool = False, ) -> StatusCode: """Write a 16-bit value to the specified memory space and offset. Corresponds to viOut16* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space into which to write. offset : int Offset (in bytes) of the address or register from which to read. data : int Data to write to bus. extended : bool, optional Use 64 bits offset independent of the platform. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def out_32( self, session: VISASession, space: constants.AddressSpace, offset: int, data: Iterable[int], extended: bool = False, ) -> StatusCode: """Write a 32-bit value to the specified memory space and offset. Corresponds to viOut32* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space into which to write. offset : int Offset (in bytes) of the address or register from which to read. data : int Data to write to bus. extended : bool, optional Use 64 bits offset independent of the platform. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def out_64( self, session: VISASession, space: constants.AddressSpace, offset: int, data: Iterable[int], extended: bool = False, ) -> StatusCode: """Write a 64-bit value to the specified memory space and offset. Corresponds to viOut64* functions of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. space : constants.AddressSpace Address space into which to write. offset : int Offset (in bytes) of the address or register from which to read. data : int Data to write to bus. extended : bool, optional Use 64 bits offset independent of the platform. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def parse_resource( self, session: VISARMSession, resource_name: str ) -> Tuple[ResourceInfo, StatusCode]: """Parse a resource string to get the interface information. Corresponds to viParseRsrc function of the VISA library. Parameters ---------- session : VISARMSession Resource Manager session (should always be the Default Resource Manager for VISA returned from open_default_resource_manager()). resource_name : str Unique symbolic name of a resource. Returns ------- ResourceInfo Resource information with interface type and board number StatusCode Return value of the library call. """ ri, status = self.parse_resource_extended(session, resource_name) if status == StatusCode.success: return ( ResourceInfo( ri.interface_type, ri.interface_board_number, None, None, None ), StatusCode.success, ) else: return ri, status
[docs] def parse_resource_extended( self, session: VISARMSession, resource_name: str ) -> Tuple[ResourceInfo, StatusCode]: """Parse a resource string to get extended interface information. Corresponds to viParseRsrcEx function of the VISA library. Parameters ---------- session : VISARMSession Resource Manager session (should always be the Default Resource Manager for VISA returned from open_default_resource_manager()). resource_name : str Unique symbolic name of a resource. Returns ------- ResourceInfo Resource information with interface type and board number StatusCode Return value of the library call. """ try: parsed = rname.parse_resource_name(resource_name) except ValueError: return ( ResourceInfo(constants.InterfaceType.unknown, 0, None, None, None), StatusCode.error_invalid_resource_name, ) board_number: Optional[int] try: # We can only get concrete classes which have one of those attributes board_number = int( parsed.board # type: ignore if hasattr(parsed, "board") else parsed.interface # type: ignore ) # In some cases the board number may not be convertible to an int # PyVISA-py serial resources on Linux for example except ValueError: board_number = None return ( ResourceInfo( parsed.interface_type_const, board_number, parsed.resource_class, str(parsed), None, ), StatusCode.success, )
[docs] def peek_8( self, session: VISASession, address: VISAMemoryAddress ) -> Tuple[int, StatusCode]: """Read an 8-bit value from the specified address. Corresponds to viPeek8 function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. Returns ------- int Data read from bus StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def peek_16( self, session: VISASession, address: VISAMemoryAddress ) -> Tuple[int, StatusCode]: """Read an 16-bit value from the specified address. Corresponds to viPeek16 function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. Returns ------- int Data read from bus StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def peek_32( self, session: VISASession, address: VISAMemoryAddress ) -> Tuple[int, StatusCode]: """Read an 32-bit value from the specified address. Corresponds to viPeek32 function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. Returns ------- int Data read from bus StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def peek_64( self, session: VISASession, address: VISAMemoryAddress ) -> Tuple[int, StatusCode]: """Read an 64-bit value from the specified address. Corresponds to viPeek64 function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. Returns ------- int Data read from bus StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def poke_8( self, session: VISASession, address: VISAMemoryAddress, data: int ) -> StatusCode: """Write an 8-bit value to the specified address. Corresponds to viPoke8 function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. data : int Data to write. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def poke_16( self, session: VISASession, address: VISAMemoryAddress, data: int ) -> StatusCode: """Write an 16-bit value to the specified address. Corresponds to viPoke16 function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. data : int Data to write. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def poke_32( self, session: VISASession, address: VISAMemoryAddress, data: int ) -> StatusCode: """Write an 32-bit value to the specified address. Corresponds to viPoke32 function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. data : int Data to write. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def poke_64( self, session: VISASession, address: VISAMemoryAddress, data: int ) -> StatusCode: """Write an 64-bit value to the specified address. Corresponds to viPoke64 function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. data : int Data to write. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def read(self, session: VISASession, count: int) -> Tuple[bytes, StatusCode]: """Reads data from device or interface synchronously. Corresponds to viRead function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. count : int Number of bytes to be read. Returns ------- bytes Date read StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def read_asynchronously( self, session: VISASession, count: int ) -> Tuple[SupportsBytes, VISAJobID, StatusCode]: """Reads data from device or interface asynchronously. Corresponds to viReadAsync function of the VISA library. Since the asynchronous operation may complete before the function call return implementation should make sure that get_buffer_from_id will be able to return the proper buffer before this method returns. Parameters ---------- session : VISASession Unique logical identifier to a session. count : int Number of bytes to be read. Returns ------- SupportsBytes Buffer that will be filled during the asynchronous operation. VISAJobID Id of the asynchronous job StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def get_buffer_from_id(self, job_id: VISAJobID) -> Optional[SupportsBytes]: """Retrieve the buffer associated with a job id created in read_asynchronously Parameters ---------- job_id : VISAJobID Id of the job for which to retrieve the buffer. Returns ------- Optional[SupportsBytes] Buffer in which the data are stored or None if the job id is not associated with any job. """ raise NotImplementedError
[docs] def read_stb(self, session: VISASession) -> Tuple[int, StatusCode]: """Reads a status byte of the service request. Corresponds to viReadSTB function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. Returns ------- int Service request status byte StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def read_to_file( self, session: VISASession, filename: str, count: int ) -> Tuple[int, StatusCode]: """Read data synchronously, and store the transferred data in a file. Corresponds to viReadToFile function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. filename : str Name of file to which data will be written. count : int Number of bytes to be read. Returns ------- int Number of bytes actually transferred StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def set_attribute( self, session: VISASession, attribute: constants.ResourceAttribute, attribute_state: Any, ) -> StatusCode: """Set the state of an attribute. Corresponds to viSetAttribute function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. attribute : constants.ResourceAttribute Attribute for which the state is to be modified. attribute_state : Any The state of the attribute to be set for the specified object. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def set_buffer( self, session: VISASession, mask: constants.BufferType, size: int ) -> StatusCode: """Set the size for the formatted I/O and/or low-level I/O communication buffer(s). Corresponds to viSetBuf function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. mask : constants.BufferType Specifies the type of buffer. size : int The size to be set for the specified buffer(s). Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def status_description( self, session: VISASession, status: StatusCode ) -> Tuple[str, StatusCode]: """Return a user-readable description of the status code passed to the operation. Corresponds to viStatusDesc function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. status : StatusCode Status code to interpret. Returns ------- str User-readable string interpretation of the status code. StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def terminate( self, session: VISASession, degree: None, job_id: VISAJobID ) -> StatusCode: """Request a VISA session to terminate normal execution of an operation. Corresponds to viTerminate function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. degree : None Not used in this version of the VISA specification. job_id : VISAJobId Specifies an operation identifier. If a user passes None as the job_id value to viTerminate(), a VISA implementation should abort any calls in the current process executing on the specified vi. Any call that is terminated this way should return VI_ERROR_ABORT. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def uninstall_handler( self, session: VISASession, event_type: constants.EventType, handler: VISAHandler, user_handle: Any = None, ) -> StatusCode: """Uninstall handlers for events. Corresponds to viUninstallHandler function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. event_type : constants.EventType Logical event identifier. handler : VISAHandler Handler to be uninstalled by a client application. user_handle: A value specified by an application that can be used for identifying handlers uniquely in a session for an event. The modified value of the user_handle as returned by install_handler should be used instead of the original value. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def unlock(self, session: VISASession) -> 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. """ raise NotImplementedError
[docs] def unmap_address(self, session: VISASession) -> StatusCode: """Unmap memory space previously mapped by map_address(). Corresponds to viUnmapAddress function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def unmap_trigger( self, session: VISASession, trigger_source: constants.InputTriggerLine, trigger_destination: constants.OutputTriggerLine, ) -> StatusCode: """Undo a previous map between a trigger source line and a destination line. Corresponds to viUnmapTrigger function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. trigger_source : constants.InputTriggerLine Source line used in previous map. trigger_destination : constants.OutputTriggerLine Destination line used in previous map. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def usb_control_in( self, session: VISASession, request_type_bitmap_field: int, request_id: int, request_value: int, index: int, length: int = 0, ) -> Tuple[bytes, StatusCode]: """Perform a USB control pipe transfer from the device. Corresponds to viUsbControlIn function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. request_type_bitmap_field : int bmRequestType parameter of the setup stage of a USB control transfer. request_id : int bRequest parameter of the setup stage of a USB control transfer. request_value : int wValue parameter of the setup stage of a USB control transfer. index : int wIndex parameter of the setup stage of a USB control transfer. This is usually the index of the interface or endpoint. length : int, optional 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. Returns ------- bytes The data buffer that receives the data from the optional data stage of the control transfer StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def usb_control_out( self, session: VISASession, request_type_bitmap_field: int, request_id: int, request_value: int, index: int, data: bytes = b"", ) -> StatusCode: """Perform a USB control pipe transfer to the device. Corresponds to viUsbControlOut function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. request_type_bitmap_field : int bmRequestType parameter of the setup stage of a USB control transfer. request_id : int bRequest parameter of the setup stage of a USB control transfer. request_value : int wValue parameter of the setup stage of a USB control transfer. index : int wIndex parameter of the setup stage of a USB control transfer. This is usually the index of the interface or endpoint. data : bytes, optional The data buffer that sends the data in the optional data stage of the control transfer. Returns ------- StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def vxi_command_query( self, session: VISASession, mode: constants.VXICommands, command: int ) -> Tuple[int, StatusCode]: """Send the device a miscellaneous command or query and/or retrieves the response to a previous query. Corresponds to viVxiCommandQuery function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. mode : constants.VXICommands Specifies whether to issue a command and/or retrieve a response. command : int The miscellaneous command to send. Returns ------- int The response retrieved from the device StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def wait_on_event( self, session: VISASession, in_event_type: constants.EventType, timeout: int ) -> Tuple[constants.EventType, VISAEventContext, 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 : constants.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 ------- constants.EventType Logical identifier of the event actually received VISAEventContext A handle specifying the unique occurrence of an event StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def write(self, session: VISASession, data: bytes) -> Tuple[int, StatusCode]: """Write data to device or interface synchronously. Corresponds to viWrite function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. data : bytes Data to be written. Returns ------- int Number of bytes actually transferred StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def write_asynchronously( self, session: VISASession, data: bytes ) -> Tuple[VISAJobID, StatusCode]: """Write data to device or interface asynchronously. Corresponds to viWriteAsync function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. data : bytes Data to be written. Returns ------- VISAJobID Job ID of this asynchronous write operation StatusCode Return value of the library call. """ raise NotImplementedError
[docs] def write_from_file( self, session: VISASession, filename: str, count: int ) -> Tuple[int, StatusCode]: """Take data from a file and write it out synchronously. Corresponds to viWriteFromFile function of the VISA library. Parameters ---------- session : VISASession Unique logical identifier to a session. filename : str Name of file from which data will be read. count : int Number of bytes to be written. Returns ------- int Number of bytes actually transferred StatusCode Return value of the library call. """ raise NotImplementedError
def list_backends() -> List[str]: """Return installed backends. Backends are installed python packages named pyvisa_<something> where <something> is the name of the backend. """ return ["ivi"] + [ name[7:] for (loader, name, ispkg) in pkgutil.iter_modules() if (name.startswith("pyvisa_") or name.startswith("pyvisa-")) and not name.endswith("-script") ] #: Maps backend name to VisaLibraryBase derived class _WRAPPERS: Dict[str, Type[VisaLibraryBase]] = {} class PyVISAModule(ModuleType): WRAPPER_CLASS: Type[VisaLibraryBase] def get_wrapper_class(backend_name: str) -> Type[VisaLibraryBase]: """Return the WRAPPER_CLASS for a given backend.""" try: return _WRAPPERS[backend_name] except KeyError: if backend_name == "ivi": from .ctwrapper import IVIVisaLibrary _WRAPPERS["ivi"] = IVIVisaLibrary return IVIVisaLibrary pkg: PyVISAModule try: pkg = cast(PyVISAModule, import_module("pyvisa_" + backend_name)) _WRAPPERS[backend_name] = cls = pkg.WRAPPER_CLASS return cls except ImportError: raise ValueError("Wrapper not found: No package named pyvisa_%s" % backend_name) def _get_default_wrapper() -> str: """Return an available default VISA wrapper as a string ('ivi' or 'py'). Use IVI if the binary is found, else try to use pyvisa-py. 'ni' VISA wrapper is NOT used since version > 1.10.0 and will be removed in 1.12 Raises ------ ValueError If no backend can be found """ from .ctwrapper import IVIVisaLibrary ivi_binary_found = bool(IVIVisaLibrary.get_library_paths()) if ivi_binary_found: logger.debug("The IVI implementation available") return "ivi" else: logger.debug("Did not find IVI binary") try: get_wrapper_class("py") # check for pyvisa-py availability logger.debug("pyvisa-py is available.") return "py" except ValueError: logger.debug("Did not find pyvisa-py package") raise ValueError( "Could not locate a VISA implementation. Install either the IVI binary or pyvisa-py." ) def open_visa_library(specification: str = "") -> VisaLibraryBase: """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. Parameters ---------- specification : str, optional The specification has 2 parts separated by a '@', ex: path/visa.dll@ivi The second part is the backend name (ivi, py, ...) while the first part will be passed to the library object. In the case of the ivi backend it should the path to the VISA library. Either part can be omitted. If the second part is omitted, the system will fall back to the ivi backend if available or the pyvisa-py backend if the first part is also omitted. """ if not specification: logger.debug("No visa library specified, trying to find alternatives.") try: specification = os.environ["PYVISA_LIBRARY"] except KeyError: logger.debug("Environment variable PYVISA_LIBRARY is unset.") wrapper: Optional[str] try: argument, wrapper = specification.split("@") except ValueError: argument = specification wrapper = None # Flag that we need a fallback, but avoid nested exceptions if wrapper is None: if argument: # some filename given wrapper = "ivi" else: wrapper = _get_default_wrapper() cls = get_wrapper_class(wrapper) try: return cls(argument) except Exception as e: logger.debug("Could not open VISA wrapper %s: %s\n%s", cls, str(argument), e) raise
[docs]class ResourceManager(object): """VISA Resource Manager.""" #: Maps (Interface Type, Resource Class) to Python class encapsulating that resource. _resource_classes: ClassVar[ Dict[Tuple[constants.InterfaceType, str], Type["Resource"]] ] = dict() #: Session handler for the resource manager. _session: Optional[VISARMSession] = None #: Reference to the VISA library used by the ResourceManager visalib: VisaLibraryBase #: Resources created by this manager to allow closing them when the manager is closed _created_resources: WeakSet #: Handler for atexit using a weakref to close _atexit_handler: Callable @classmethod def register_resource_class( cls, interface_type: constants.InterfaceType, resource_class: str, python_class: Type["Resource"], ) -> None: """Register a class for a specific interface type, resource class pair. Parameters ---------- interface_type : constants.InterfaceType Interface type for which to use the provided class. resource_class : str Resource class (INSTR, INTFC, ...) for which to use the provided class. python_class : Type[Resource] Subclass of ``Resource`` to use when opening a resource matching the specified interface type and resource class. """ if (interface_type, resource_class) in cls._resource_classes: logger.warning( "%s is already registered in the ResourceManager. " "Overwriting with %s" % ((interface_type, resource_class), python_class) ) # If the class already has this attribute, it means that a parent class # was registered first. We need to copy the current set and extend it. attrs: Set[Type[attributes.Attribute]] = copy.copy( getattr(python_class, "visa_attributes_classes", set()) ) for attr in chain( attributes.AttributesPerResource[(interface_type, resource_class)], attributes.AttributesPerResource[attributes.AllSessionTypes], ): attrs.add(attr) # Error on non-properly set descriptor (this ensures that we are # consistent) if attr.py_name != "" and not hasattr(python_class, attr.py_name): raise TypeError( "%s was expected to have a visa attribute %s" % (python_class, attr.py_name) ) setattr(python_class, "visa_attributes_classes", attrs) cls._resource_classes[(interface_type, resource_class)] = python_class def __new__( cls: Type["ResourceManager"], visa_library: Union[str, VisaLibraryBase] = "" ) -> "ResourceManager": """Create a new resource manager tied to the specified VISA library. Parameters ---------- visa_library : Union[str, VisaLibraryBase] Either a fully initialized VisaLibraryBase subclass instance or a str specification (see open_visa_library for the format). """ if not isinstance(visa_library, VisaLibraryBase): visa_library = open_visa_library(visa_library) if visa_library.resource_manager is not None: obj = visa_library.resource_manager logger.debug("Reusing ResourceManager with session %s", obj.session) return obj obj = super(ResourceManager, cls).__new__(cls) obj.session, err = visa_library.open_default_resource_manager() obj.visalib = visa_library obj.visalib.resource_manager = obj obj._created_resources = WeakSet() # Register an atexit handler to ensure the Resource Manager is properly # closed. close_ref = WeakMethod(obj.close) # type: ignore def call_close(): meth = close_ref() if meth: meth() atexit.register(call_close) obj._atexit_handler = call_close # type: ignore logger.debug("Created ResourceManager with session %s", obj.session) return obj @property def session(self) -> VISARMSession: """Resource Manager session handle. Raises ------ errors.InvalidSession Raised if the session is closed. """ if self._session is None: raise errors.InvalidSession() return self._session @session.setter def session(self, value: Optional[VISARMSession]) -> None: self._session = value def __str__(self) -> str: return "Resource Manager of %s" % self.visalib def __repr__(self) -> str: return "<ResourceManager(%r)>" % self.visalib def __del__(self) -> None: if self._session is not None: self.close() def ignore_warning(self, *warnings_constants: StatusCode) -> ContextManager: """Ignoring warnings context manager for the current resource. Parameters ---------- warnings_constants : StatusCode Constants identifying the warnings to ignore. """ return self.visalib.ignore_warning(self.session, *warnings_constants) @property def last_status(self) -> StatusCode: """Last status code returned for an operation with this Resource Manager.""" return self.visalib.get_last_status_in_session(self.session)
[docs] def close(self) -> None: """Close the resource manager session. Notes ----- Since the resource manager session is shared between instances this will also terminate connections obtained from other ResourceManager instances. """ atexit.unregister(self._atexit_handler) try: logger.debug("Closing ResourceManager (session: %s)", self.session) # Cleanly close all resources when closing the manager. for resource in self._created_resources: resource.close() self.visalib.close(self.session) # mypy don't get that we can set a value we cannot get self.session = None # type: ignore self.visalib.resource_manager = None except errors.InvalidSession: pass
[docs] def list_resources(self, query: str = "?*::INSTR") -> Tuple[str, ...]: r"""Return a tuple of all connected devices matching query. Notes ----- The query uses the VISA Resource Regular Expression syntax - which is not the same as the Python regular expression syntax. (see below) The VISA Resource Regular Expression syntax is defined in the VISA Library specification: http://www.ivifoundation.org/docs/vpp43.pdf Symbol Meaning ---------- ---------- ? Matches any one character. \ Makes the character that follows it an ordinary character instead of special character. For example, when a question mark follows a backslash (\?), it matches the ? character instead of any one character. [list] Matches any one character from the enclosed list. You can use a hyphen to match a range of characters. [^list] Matches any character not in the enclosed list. You can use a hyphen to match a range of characters. * Matches 0 or more occurrences of the preceding character or expression. + Matches 1 or more occurrences of the preceding character or expression. Exp|exp Matches either the preceding or following expression. The or operator | matches the entire expression that precedes or follows it and not just the character that precedes or follows it. For example, VXI|GPIB means (VXI)|(GPIB), not VX(I|G)PIB. (exp) Grouping characters or expressions. Thus the default query, '?*::INSTR', matches any sequences of characters ending ending with '::INSTR'. On some platforms, devices that are already open are not returned. """ return self.visalib.list_resources(self.session, query)
[docs] def list_resources_info(self, query: str = "?*::INSTR") -> Dict[str, ResourceInfo]: """Get extended information about all connected devices matching query. For details of the VISA Resource Regular Expression syntax used in query, refer to list_resources(). Returns ------- Dict[str, ResourceInfo] Mapping of resource name to ResourceInfo """ return dict( (resource, self.resource_info(resource)) for resource in self.list_resources(query) )
def list_opened_resources(self) -> List["Resource"]: """Return a list of all the opened resources.""" opened = [] for resource in self._created_resources: try: resource.session except errors.InvalidSession: pass else: opened.append(resource) return opened
[docs] def resource_info(self, resource_name: str, extended: bool = True) -> ResourceInfo: """Get the (extended) information of a particular resource. Parameters ---------- resource_name : str Unique symbolic name of a resource. extended : bool, optional Also get extended information (ie. resource_class, resource_name, alias) """ if extended: ret, err = self.visalib.parse_resource_extended(self.session, resource_name) else: ret, err = self.visalib.parse_resource(self.session, resource_name) return ret
[docs] def open_bare_resource( self, resource_name: str, access_mode: constants.AccessModes = constants.AccessModes.no_lock, open_timeout: int = constants.VI_TMO_IMMEDIATE, ) -> Tuple[VISASession, StatusCode]: """Open the specified resource without wrapping into a class. Parameters ---------- resource_name : str Name or alias of the resource to open. access_mode : constants.AccessModes, optional Specifies the mode by which the resource is to be accessed, by default constants.AccessModes.no_lock open_timeout : int, optional If the ``access_mode`` parameter requests a lock, then this parameter specifies the absolute time period (in milliseconds) that the resource waits to get unlocked before this operation returns an error, by default constants.VI_TMO_IMMEDIATE. Returns ------- VISASession Unique logical identifier reference to a session. StatusCode Return value of the library call. """ return self.visalib.open(self.session, resource_name, access_mode, open_timeout)
[docs] def open_resource( self, resource_name: str, access_mode: constants.AccessModes = constants.AccessModes.no_lock, open_timeout: int = constants.VI_TMO_IMMEDIATE, resource_pyclass: Optional[Type["Resource"]] = None, **kwargs: Any, ) -> "Resource": """Return an instrument for the resource name. Parameters ---------- resource_name : str Name or alias of the resource to open. access_mode : constants.AccessModes, optional Specifies the mode by which the resource is to be accessed, by default constants.AccessModes.no_lock open_timeout : int, optional If the ``access_mode`` parameter requests a lock, then this parameter specifies the absolute time period (in milliseconds) that the resource waits to get unlocked before this operation returns an error, by default constants.VI_TMO_IMMEDIATE. resource_pyclass : Optional[Type[Resource]], optional Resource Python class to use to instantiate the Resource. Defaults to None: select based on the resource name. kwargs : Any Keyword arguments to be used to change instrument attributes after construction. Returns ------- Resource Subclass of Resource matching the resource. """ if resource_pyclass is None: info = self.resource_info(resource_name, extended=True) try: # When using querying extended resource info the resource_class is not # None resource_pyclass = self._resource_classes[ (info.interface_type, info.resource_class) # type: ignore ] except KeyError: resource_pyclass = self._resource_classes[ (constants.InterfaceType.unknown, "") ] logger.warning( "There is no class defined for %r. Using Resource", (info.interface_type, info.resource_class), ) if hasattr(self.visalib, "open_resource"): res = self.visalib.open_resource( # type: ignore resource_name, access_mode, open_timeout, resource_pyclass, **kwargs ) else: res = resource_pyclass(self, resource_name) for key in kwargs.keys(): try: getattr(res, key) present = True except AttributeError: present = False except errors.InvalidSession: present = True if not present: raise ValueError( "%r is not a valid attribute for type %s" % (key, res.__class__.__name__) ) res.open(access_mode, open_timeout) for key, value in kwargs.items(): setattr(res, key, value) self._created_resources.add(res) return res