# -*- coding: utf-8 -*- """Defines VPP 4.3.2 wrapping functions using ctypes, adding signatures to the library. 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 warnings from contextlib import contextmanager from ctypes import ( POINTER, byref, c_double, c_long, c_void_p, c_wchar_p, create_string_buffer, ) from functools import update_wrapper from threading import Lock from typing import Any, Callable, Optional, Tuple from pyvisa import attributes, constants, ctwrapper, typing from pyvisa.highlevel import ResourceInfo from . import types from .types import ( FUNCTYPE, ViAccessMode, ViAChar, ViAddr, ViAttr, ViAttrState, ViAUInt8, ViAUInt16, ViAUInt32, ViAUInt64, ViBoolean, ViBuf, ViBusAddress, ViBusAddress64, ViBusSize, ViEvent, ViEventFilter, ViEventType, ViFindList, ViHndlr, ViInt16, ViJobId, ViKeyId, ViObject, ViPAddr, ViPBuf, ViPBusAddress, ViPEvent, ViPEventType, ViPFindList, ViPJobId, ViPSession, ViPUInt8, ViPUInt16, ViPUInt32, ViPUInt64, ViRsrc, ViSession, ViStatus, ViString, ViUInt8, ViUInt16, ViUInt32, ViUInt64, buffer_to_text, ) visa_functions = [ "assert_interrupt_signal", "assert_trigger", "assert_utility_signal", "buffer_read", "buffer_write", "clear", "close", "disable_event", "discard_events", "enable_event", "_find_next", "_find_resources", "flush", "get_attribute", "gpib_command", "gpib_control_atn", "gpib_control_ren", "gpib_pass_control", "gpib_send_ifc", "in_16", "in_32", "in_8", "install_handler", "lock", "map_address", "map_trigger", "memory_allocation", "memory_free", "move", "move_asynchronously", "move_in_16", "move_in_32", "move_in_8", "move_out_16", "move_out_32", "move_out_8", "open", "open_default_resource_manager", "out_16", "out_32", "out_8", "parse_resource", "parse_resource_extended", "peek_16", "peek_32", "peek_8", "poke_16", "poke_32", "poke_8", "read", "read_to_file", "read_stb", "set_attribute", "set_buffer", "status_description", "terminate", "uninstall_handler", "unlock", "unmap_address", "unmap_trigger", "usb_control_in", "usb_control_out", "vxi_command_query", "wait_on_event", "write", "write_asynchronously", "write_from_file", "in_64", "move_in_64", "out_64", "move_out_64", "poke_64", "peek_64", ] __all__ = ["visa_functions", "set_signatures"] + visa_functions VI_SPEC_VERSION = 0x00300000 #: Global lock to ensure that we cannot have one thread change the type while #: another is trying to interact with VISA ViHndlr_lock = Lock() @contextmanager def set_user_handle_type(library, user_handle: Any): """Set the type of the user handle to install and uninstall handler signature. Parameters ---------- library : The visa library wrapped by ctypes. user_handle : User handle used when registering an event handler. Use None for a void_p. """ with ViHndlr_lock: # Actually, it's not necessary to change ViHndlr *globally*. However, # I don't want to break symmetry too much with all the other VPP43 # routines. global ViHndlr if user_handle is None: user_handle_p = c_void_p else: user_handle_p = POINTER(type(user_handle)) # type: ignore ViHndlr = FUNCTYPE(ViStatus, ViSession, ViEventType, ViEvent, user_handle_p) library.viInstallHandler.argtypes = [ ViSession, ViEventType, ViHndlr, user_handle_p, ] library.viUninstallHandler.argtypes = [ ViSession, ViEventType, ViHndlr, user_handle_p, ] yield def set_signatures( library, errcheck: Optional[Callable[[int, Callable, tuple], int]] = None ): """Set the signatures of most visa functions in the library. All instrumentation related functions are specified here. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL The visa library wrapped by ctypes. errcheck : Optional[Callable[[int, Callable, tuple], int]] Error checking callable used for visa functions that return ViStatus. It should be take three arguments (result, func, arguments). See errcheck in ctypes. """ # Somehow hasattr(library, '_functions') segfaults in cygwin (See #131) if "_functions" not in dir(library): library._functions = [] library._functions_failed = [] def _applier(restype, errcheck_): def _internal(function_name, argtypes, required=False): try: set_signature(library, function_name, argtypes, restype, errcheck_) library._functions.append(function_name) except AttributeError: library._functions_failed.append(function_name) if required: raise return _internal # Visa functions with ViStatus return code apply = _applier(ViStatus, errcheck) apply("viAssertIntrSignal", [ViSession, ViInt16, ViUInt32]) apply("viAssertTrigger", [ViSession, ViUInt16]) apply("viAssertUtilSignal", [ViSession, ViUInt16]) apply("viBufRead", [ViSession, ViPBuf, ViUInt32, ViPUInt32]) apply("viBufWrite", [ViSession, ViBuf, ViUInt32, ViPUInt32]) apply("viClear", [ViSession]) apply("viClose", [ViObject]) apply("viDisableEvent", [ViSession, ViEventType, ViUInt16]) apply("viDiscardEvents", [ViSession, ViEventType, ViUInt16]) apply("viEnableEvent", [ViSession, ViEventType, ViUInt16, ViEventFilter]) apply("viFindNext", [ViSession, ViAChar]) apply("viFindRsrc", [ViSession, ViString, ViPFindList, ViPUInt32, ViAChar]) apply("viFlush", [ViSession, ViUInt16]) apply("viGetAttribute", [ViObject, ViAttr, c_void_p]) apply("viGpibCommand", [ViSession, ViBuf, ViUInt32, ViPUInt32]) apply("viGpibControlATN", [ViSession, ViUInt16]) apply("viGpibControlREN", [ViSession, ViUInt16]) apply("viGpibPassControl", [ViSession, ViUInt16, ViUInt16]) apply("viGpibSendIFC", [ViSession]) apply("viIn8", [ViSession, ViUInt16, ViBusAddress, ViPUInt8]) apply("viIn16", [ViSession, ViUInt16, ViBusAddress, ViPUInt16]) apply("viIn32", [ViSession, ViUInt16, ViBusAddress, ViPUInt32]) apply("viIn64", [ViSession, ViUInt16, ViBusAddress, ViPUInt64]) apply("viIn8Ex", [ViSession, ViUInt16, ViBusAddress64, ViPUInt8]) apply("viIn16Ex", [ViSession, ViUInt16, ViBusAddress64, ViPUInt16]) apply("viIn32Ex", [ViSession, ViUInt16, ViBusAddress64, ViPUInt32]) apply("viIn64Ex", [ViSession, ViUInt16, ViBusAddress64, ViPUInt64]) apply("viInstallHandler", [ViSession, ViEventType, ViHndlr, ViAddr]) apply("viLock", [ViSession, ViAccessMode, ViUInt32, ViKeyId, ViAChar]) apply( "viMapAddress", [ViSession, ViUInt16, ViBusAddress, ViBusSize, ViBoolean, ViAddr, ViPAddr], ) apply("viMapTrigger", [ViSession, ViInt16, ViInt16, ViUInt16]) apply("viMemAlloc", [ViSession, ViBusSize, ViPBusAddress]) apply("viMemFree", [ViSession, ViBusAddress]) apply( "viMove", [ ViSession, ViUInt16, ViBusAddress, ViUInt16, ViUInt16, ViBusAddress, ViUInt16, ViBusSize, ], ) apply( "viMoveAsync", [ ViSession, ViUInt16, ViBusAddress, ViUInt16, ViUInt16, ViBusAddress, ViUInt16, ViBusSize, ViPJobId, ], ) apply("viMoveIn8", [ViSession, ViUInt16, ViBusAddress, ViBusSize, ViAUInt8]) apply("viMoveIn16", [ViSession, ViUInt16, ViBusAddress, ViBusSize, ViAUInt16]) apply("viMoveIn32", [ViSession, ViUInt16, ViBusAddress, ViBusSize, ViAUInt32]) apply("viMoveIn64", [ViSession, ViUInt16, ViBusAddress, ViBusSize, ViAUInt64]) apply("viMoveIn8Ex", [ViSession, ViUInt16, ViBusAddress64, ViBusSize, ViAUInt8]) apply("viMoveIn16Ex", [ViSession, ViUInt16, ViBusAddress64, ViBusSize, ViAUInt16]) apply("viMoveIn32Ex", [ViSession, ViUInt16, ViBusAddress64, ViBusSize, ViAUInt32]) apply("viMoveIn64Ex", [ViSession, ViUInt16, ViBusAddress64, ViBusSize, ViAUInt64]) apply("viMoveOut8", [ViSession, ViUInt16, ViBusAddress, ViBusSize, ViAUInt8]) apply("viMoveOut16", [ViSession, ViUInt16, ViBusAddress, ViBusSize, ViAUInt16]) apply("viMoveOut32", [ViSession, ViUInt16, ViBusAddress, ViBusSize, ViAUInt32]) apply("viMoveOut64", [ViSession, ViUInt16, ViBusAddress, ViBusSize, ViAUInt64]) apply("viMoveOut8Ex", [ViSession, ViUInt16, ViBusAddress64, ViBusSize, ViAUInt8]) apply("viMoveOut16Ex", [ViSession, ViUInt16, ViBusAddress64, ViBusSize, ViAUInt16]) apply("viMoveOut32Ex", [ViSession, ViUInt16, ViBusAddress64, ViBusSize, ViAUInt32]) apply("viMoveOut64Ex", [ViSession, ViUInt16, ViBusAddress64, ViBusSize, ViAUInt64]) apply( "viOpen", [ViSession, ViRsrc, ViAccessMode, ViUInt32, ViPSession], required=True ) apply("viOpenDefaultRM", [ViPSession], required=True) apply("viOut8", [ViSession, ViUInt16, ViBusAddress, ViUInt8]) apply("viOut16", [ViSession, ViUInt16, ViBusAddress, ViUInt16]) apply("viOut32", [ViSession, ViUInt16, ViBusAddress, ViUInt32]) apply("viOut64", [ViSession, ViUInt16, ViBusAddress, ViUInt64]) apply("viOut8Ex", [ViSession, ViUInt16, ViBusAddress64, ViUInt8]) apply("viOut16Ex", [ViSession, ViUInt16, ViBusAddress64, ViUInt16]) apply("viOut32Ex", [ViSession, ViUInt16, ViBusAddress64, ViUInt32]) apply("viOut64Ex", [ViSession, ViUInt16, ViBusAddress64, ViUInt64]) apply("viParseRsrc", [ViSession, ViRsrc, ViPUInt16, ViPUInt16]) apply( "viParseRsrcEx", [ViSession, ViRsrc, ViPUInt16, ViPUInt16, ViAChar, ViAChar, ViAChar], ) apply("viRead", [ViSession, ViPBuf, ViUInt32, ViPUInt32]) apply("viReadAsync", [ViSession, ViPBuf, ViUInt32, ViPJobId]) apply("viReadSTB", [ViSession, ViPUInt16]) apply("viReadToFile", [ViSession, ViString, ViUInt32, ViPUInt32]) apply("viSetAttribute", [ViObject, ViAttr, ViAttrState]) apply("viSetBuf", [ViSession, ViUInt16, ViUInt32]) apply("viStatusDesc", [ViObject, ViStatus, ViAChar]) apply("viTerminate", [ViSession, ViUInt16, ViJobId]) apply("viUninstallHandler", [ViSession, ViEventType, ViHndlr, ViAddr]) apply("viUnlock", [ViSession]) apply("viUnmapAddress", [ViSession]) apply("viUnmapTrigger", [ViSession, ViInt16, ViInt16]) apply( "viUsbControlIn", [ViSession, ViInt16, ViInt16, ViUInt16, ViUInt16, ViUInt16, ViPBuf, ViPUInt16], ) apply( "viUsbControlOut", [ViSession, ViInt16, ViInt16, ViUInt16, ViUInt16, ViUInt16, ViPBuf], ) # The following "V" routines are *not* implemented in PyVISA, and will # never be: viVPrintf, viVQueryf, viVScanf, viVSPrintf, viVSScanf apply("viVxiCommandQuery", [ViSession, ViUInt16, ViUInt32, ViPUInt32]) apply("viWaitOnEvent", [ViSession, ViEventType, ViUInt32, ViPEventType, ViPEvent]) apply("viWrite", [ViSession, ViBuf, ViUInt32, ViPUInt32]) apply("viWriteAsync", [ViSession, ViBuf, ViUInt32, ViPJobId]) apply("viWriteFromFile", [ViSession, ViString, ViUInt32, ViPUInt32]) # Functions that return void. apply = _applier(None, None) apply("viPeek8", [ViSession, ViAddr, ViPUInt8]) apply("viPeek16", [ViSession, ViAddr, ViPUInt16]) apply("viPeek32", [ViSession, ViAddr, ViPUInt32]) apply("viPeek64", [ViSession, ViAddr, ViPUInt64]) apply("viPoke8", [ViSession, ViAddr, ViUInt8]) apply("viPoke16", [ViSession, ViAddr, ViUInt16]) apply("viPoke32", [ViSession, ViAddr, ViUInt32]) apply("viPoke64", [ViSession, ViAddr, ViUInt64]) def set_signature( library, function_name: str, argtypes: tuple, restype, errcheck: Optional[Callable[[int, Callable, tuple], int]], ): """Set the signature of single function in a library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. function_name : str Name of the function as appears in the header file. argtypes : tuple ctypes types to specify the argument types that the function accepts. restype : A ctypes type to specify the result type of the foreign function. Use None for void, a function not returning anything. errcheck : Optional[Callable[[int, Callable, tuple], int]] Error checking callable used for visa functions that return ViStatus. It should be take three arguments (result, func, arguments). See errcheck in ctypes. """ func = getattr(library, function_name) func.argtypes = argtypes if restype is not None: func.restype = restype if errcheck is not None: func.errcheck = errcheck # The VPP-4.3.2 routines # Usually, there is more than one way to pass parameters to ctypes calls. The # ctypes policy used in this code goes as follows: # # * Null pointers are passed as "None" rather than "0". This is a little bit # unfortunate, since the VPP specification calls this "VI_NULL", but I can't # use "VI_NULL" since it's an integer and may not be compatible with a # pointer type (don't know whether this is really dangerous). # # * Strings must have been created with "create_string_buffer" and are passed # without any further conversion; they stand in the parameter list as is. # The same applies to pseudo-string types as ViRsrc or VuBuf. Their Pythonic # counterpats are strings as well. # # * All other types are explicitly cast using the types defined by ctypes' # "restype". # # Further notes: # # * The following Python routines take and give handles as ctypes objects. # Since the user shouldn't be interested in handle values anyway, I see no # point in converting them to Python strings or integers. # # * All other parameters are natural Python types, i.e. strings (may contain # binary data) and integers. The same is true for return values. # # * The original VPP function signatures cannot be realised in Python, at least # not in a sensible way, because a) Python has no real call-by-reference, and # b) Python allows for more elegant solutions, e.g. using len(buffer) instead # of a separate "count" parameter, or using tuples as return values. # # Therefore, all function signatures have been carefully adjusted. I think # this is okay, since the original standard must be adopted to at least C and # Visual Basic anyway, with slight modifications. I also made the function # names and parameters more legible, but in a way that it's perfectly clear # which original function is meant. # # The important thing is that the semantics of functions and parameters are # totally intact, and the inner order of parameters, too. There is a 1:1 # mapping. def assert_interrupt_signal(library, session, mode, status_id): """Asserts the specified interrupt or signal. Corresponds to viAssertIntrSignal function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ return library.viAssertIntrSignal(session, mode, status_id) def assert_trigger(library, session, protocol): """Assert software or hardware trigger. Corresponds to viAssertTrigger function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. protocol : constants.TriggerProtocol Trigger protocol to use during assertion. Returns ------- constants.StatusCode Return value of the library call. """ return library.viAssertTrigger(session, protocol) def assert_utility_signal(library, session, line): """Assert or deassert the specified utility bus signal. Corresponds to viAssertUtilSignal function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. line : constants.UtilityBusSignal Specifies the utility bus signal to assert. Returns ------- constants.StatusCode Return value of the library call. """ return library.viAssertUtilSignal(session, line) def buffer_read(library, session, count): """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 ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. count : int Number of bytes to be read. Returns ------- dbytes Data read constants.StatusCode Return value of the library call. """ buffer = create_string_buffer(count) return_count = ViUInt32() ret = library.viBufRead(session, buffer, count, byref(return_count)) return buffer.raw[: return_count.value], ret def buffer_write(library, session, data): """Writes data to a formatted I/O write buffer synchronously. Corresponds to viBufWrite function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. data : bytes Data to be written. Returns ------- int number of written bytes constants.StatusCode return value of the library call. """ return_count = ViUInt32() # [ViSession, ViBuf, ViUInt32, ViPUInt32] ret = library.viBufWrite(session, data, len(data), byref(return_count)) return return_count.value, ret def clear(library, session): """Clears a device. Corresponds to viClear function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. Returns ------- constants.StatusCode Return value of the library call. """ return library.viClear(session) def close(library, session): """Closes the specified session, event, or find list. Corresponds to viClose function of the VISA library. Parameters --------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : Union[VISASession, VISAEventContext, VISARMSession] Unique logical identifier to a session, event, resource manager. Returns ------- constants.StatusCode Return value of the library call. """ return library.viClose(session) def disable_event(library, session, event_type, mechanism): """Disable notification for an event type(s) via the specified mechanism(s). Corresponds to viDisableEvent function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. event_type : constants.EventType Event type. mechanism : constants.EventMechanism Event handling mechanisms to be disabled. Returns ------- constants.StatusCode Return value of the library call. """ return library.viDisableEvent(session, event_type, mechanism) def discard_events(library, session, event_type, mechanism): """Discard event occurrences for a given type and mechanisms in a session. Corresponds to viDiscardEvents function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. event_type : constans.EventType Logical event identifier. mechanism : constants.EventMechanism Specifies event handling mechanisms to be discarded. Returns ------- constants.StatusCode Return value of the library call. """ return library.viDiscardEvents(session, event_type, mechanism) 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. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ if context is None: context = constants.VI_NULL elif context != constants.VI_NULL: warnings.warn("In enable_event, context will be set VI_NULL.") context = constants.VI_NULL # according to spec VPP-4.3, section 3.7.3.1 return library.viEnableEvent(session, event_type, mechanism, context) def _find_next(library, find_list: ViFindList) -> Tuple[str, constants.StatusCode]: """Get next resource from the list of resources. The list of resources should be obtained from a previous call to find_resources(). Corresponds to viFindNext function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. find_list : Describes a find list. This parameter must be created by find_resources(). Returns ------- str String identifying the location of a device constants.StatusCode Return value of the library call. """ instrument_description = create_string_buffer(constants.VI_FIND_BUFLEN) ret = library.viFindNext(find_list, instrument_description) return buffer_to_text(instrument_description), ret def _find_resources(library, session: typing.VISARMSession, query: str): """Queries VISA to locate the resources associated with a specified interface. Corresponds to viFindRsrc function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : typing.VISARMSession Unique logical identifier to the ResourceManger session (unused, just to uniform signatures). query : str A regular expression followed by an optional logical expression. Use '?*' for all. Returns ------- ViFindList Opaque object to pass to `_find_next` to access the other devices resource name. int Number of identified devices. str Resource name of the first identified device constants.StatusCode Return value of the library call. """ find_list = ViFindList() return_counter = ViUInt32() instrument_description = create_string_buffer(constants.VI_FIND_BUFLEN) ret = library.viFindRsrc( session, query, byref(find_list), byref(return_counter), instrument_description ) return find_list, return_counter.value, buffer_to_text(instrument_description), ret def flush(library, session, mask): """Retrieves the state of an attribute. Corresponds to viGetAttribute function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ return library.viFlush(session, mask) def get_attribute(library, session, attribute): """Retrieves the state of an attribute. Corresponds to viGetAttribute function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ attr = attributes.AttributesByID[attribute] datatype = getattr(types, attr.visa_type) if datatype == ViString: attribute_state = create_string_buffer(256) ret = library.viGetAttribute(session, attribute, attribute_state) return buffer_to_text(attribute_state), ret # There are only 2 buffer attribute, the one we do not handle if the one # to async read that is handled at a higher since we pass the buffer ourself elif datatype == ViBuf: if attr.visa_name == "VI_ATTR_USB_RECV_INTR_DATA": length = get_attribute( library, session, constants.VI_ATTR_USB_RECV_INTR_SIZE ) attribute_state = (ViUInt8 * length)() ret = library.viGetAttribute(session, attribute, byref(attribute_state)) return list(attribute_state), ret else: raise AttributeError("%s cannot be accessed directly" % attr.visa_name) else: attribute_state = datatype() ret = library.viGetAttribute(session, attribute, byref(attribute_state)) return attribute_state.value, ret def gpib_command(library, session, data): """Write GPIB command bytes on the bus. Corresponds to viGpibCommand function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. data : bytes Data to write. Returns ------- int Number of written bytes constants.StatusCode Return value of the library call. """ return_count = ViUInt32() # [ViSession, ViBuf, ViUInt32, ViPUInt32] ret = library.viGpibCommand(session, data, len(data), byref(return_count)) return return_count.value, ret def gpib_control_atn(library, session, mode): """Specifies the state of the ATN line and the local active controller state. Corresponds to viGpibControlATN function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. mode : constants.ATNLineOperation State of the ATN line and optionally the local active controller state. Returns ------- constants.StatusCode Return value of the library call. """ return library.viGpibControlATN(session, mode) def gpib_control_ren(library, session, mode): """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 ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. mode : constants.RENLineOperation State of the REN line and optionally the device remote/local state. Returns ------- constants.StatusCode Return value of the library call. """ return library.viGpibControlREN(session, mode) def gpib_pass_control(library, session, primary_address, secondary_address): """Tell a GPIB device to become controller in charge (CIC). Corresponds to viGpibPassControl function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ return library.viGpibPassControl(session, primary_address, secondary_address) def gpib_send_ifc(library, session): """Pulse the interface clear line (IFC) for at least 100 microseconds. Corresponds to viGpibSendIFC function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. Returns ------- constants.StatusCode Return value of the library call. """ return library.viGpibSendIFC(session) def in_8(library, 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. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ value_8 = ViUInt8() if extended: ret = library.viIn8Ex(session, space, offset, byref(value_8)) else: ret = library.viIn8(session, space, offset, byref(value_8)) return value_8.value, ret def in_16(library, 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. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ value_16 = ViUInt16() if extended: ret = library.viIn16Ex(session, space, offset, byref(value_16)) else: ret = library.viIn16(session, space, offset, byref(value_16)) return value_16.value, ret def in_32(library, 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. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ value_32 = ViUInt32() if extended: ret = library.viIn32Ex(session, space, offset, byref(value_32)) else: ret = library.viIn32(session, space, offset, byref(value_32)) return value_32.value, ret def in_64(library, 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. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ value_64 = ViUInt64() if extended: ret = library.viIn64Ex(session, space, offset, byref(value_64)) else: ret = library.viIn64(session, space, offset, byref(value_64)) return value_64.value, ret def install_handler( library, session, event_type, handler, user_handle: Any ) -> Tuple[typing.VISAHandler, Any, Any, constants.StatusCode]: """Install handlers for event callbacks. Corresponds to viInstallHandler function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 : constants.StatusCode Return value of the library call """ # Should be Optional[_CData] but that type cannot be imported converted_user_handle: object = None if user_handle is not None: if isinstance(user_handle, int): converted_user_handle = c_long(user_handle) elif isinstance(user_handle, float): converted_user_handle = c_double(user_handle) elif isinstance(user_handle, str): converted_user_handle = c_wchar_p(user_handle) elif isinstance(user_handle, list): for element in user_handle: if not isinstance(element, int): # Mypy cannot track the fact that the list has to contain float converted_user_handle = (c_double * len(user_handle))( # type: ignore *tuple(user_handle) ) break else: converted_user_handle = (c_long * len(user_handle))(*tuple(user_handle)) else: try: # check if it is already a ctypes byref(user_handle) converted_user_handle = user_handle except TypeError: raise TypeError( "Type not allowed as user handle: %s" % type(user_handle) ) with set_user_handle_type(library, converted_user_handle): if ctwrapper.WRAP_HANDLER: # Wrap the handler to provide a non-wrapper specific interface def handler_wrapper( ctype_session, ctype_event_type, ctype_event_context, ctype_user_handle ): handler( ctype_session.value, ctype_event_type, ctype_event_context.value, ctype_user_handle.contents if ctype_user_handle else ctype_user_handle, ) return 0 update_wrapper(handler_wrapper, handler) else: handler_wrapper = handler converted_handler = ViHndlr(handler_wrapper) if user_handle is None: ret = library.viInstallHandler(session, event_type, converted_handler, None) else: ret = library.viInstallHandler( session, event_type, converted_handler, byref(converted_user_handle), # type: ignore ) return handler, converted_user_handle, converted_handler, ret def lock(library, session, lock_type, timeout, requested_key=None): """Establishes an access mode to the specified resources. Corresponds to viLock function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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. constants.StatusCode Return value of the library call. """ if lock_type == constants.AccessModes.exclusive_lock: requested_key = None access_key = None else: access_key = create_string_buffer(256) ret = library.viLock(session, lock_type, timeout, requested_key, access_key) if access_key is None: return None, ret else: return access_key.value, ret def map_address( library, 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. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ if access is False: access = constants.VI_FALSE elif access != constants.VI_FALSE: warnings.warn("In enable_event, context will be set VI_NULL.") access = constants.VI_FALSE address = ViAddr() ret = library.viMapAddress( session, map_space, map_base, map_size, access, suggested, byref(address) ) return address, ret def map_trigger(library, 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. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ return library.viMapTrigger(session, trigger_source, trigger_destination, mode) def memory_allocation(library, session, size, extended=False): """Allocate memory from a resource's memory region. Corresponds to viMemAlloc* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ offset = ViBusAddress() if extended: ret = library.viMemAllocEx(session, size, byref(offset)) else: ret = library.viMemAlloc(session, size, byref(offset)) return offset, ret def memory_free(library, session, offset, extended=False): """Frees memory previously allocated using the memory_allocation() operation. Corresponds to viMemFree* function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ if extended: return library.viMemFreeEx(session, offset) else: return library.viMemFree(session, offset) def move( library, 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. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ return library.viMove( session, source_space, source_offset, source_width, destination_space, destination_offset, destination_width, length, ) def move_asynchronously( library, 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. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ job_id = ViJobId() ret = library.viMoveAsync( session, source_space, source_offset, source_width, destination_space, destination_offset, destination_width, length, byref(job_id), ) return job_id, ret def move_in_8(library, session, space, offset, length, extended=False): """Moves an 8-bit block of data to local memory. Corresponds to viMoveIn8* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 : constants.StatusCode Return value of the library call. """ buffer_8 = (ViUInt8 * length)() if extended: ret = library.viMoveIn8Ex(session, space, offset, length, buffer_8) else: ret = library.viMoveIn8(session, space, offset, length, buffer_8) return list(buffer_8), ret def move_in_16(library, session, space, offset, length, extended=False): """Moves an 16-bit block of data to local memory. Corresponds to viMoveIn816 functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 : constants.StatusCode Return value of the library call. """ buffer_16 = (ViUInt16 * length)() if extended: ret = library.viMoveIn16Ex(session, space, offset, length, buffer_16) else: ret = library.viMoveIn16(session, space, offset, length, buffer_16) return list(buffer_16), ret def move_in_32(library, session, space, offset, length, extended=False): """Moves an 32-bit block of data to local memory. Corresponds to viMoveIn32* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 : constants.StatusCode Return value of the library call. """ buffer_32 = (ViUInt32 * length)() if extended: ret = library.viMoveIn32Ex(session, space, offset, length, buffer_32) else: ret = library.viMoveIn32(session, space, offset, length, buffer_32) return list(buffer_32), ret def move_in_64(library, session, space, offset, length, extended=False): """Moves an 64-bit block of data to local memory. Corresponds to viMoveIn8* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 : constants.StatusCode Return value of the library call. """ buffer_64 = (ViUInt64 * length)() if extended: ret = library.viMoveIn64Ex(session, space, offset, length, buffer_64) else: ret = library.viMoveIn64(session, space, offset, length, buffer_64) return list(buffer_64), ret def move_out_8(library, session, space, offset, length, data, extended=False): """Moves an 8-bit block of data from local memory. Corresponds to viMoveOut8* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ converted_buffer = (ViUInt8 * length)(*tuple(data)) if extended: return library.viMoveOut8Ex(session, space, offset, length, converted_buffer) else: return library.viMoveOut8(session, space, offset, length, converted_buffer) def move_out_16(library, session, space, offset, length, data, extended=False): """Moves an 16-bit block of data from local memory. Corresponds to viMoveOut16* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ converted_buffer = (ViUInt16 * length)(*tuple(data)) if extended: return library.viMoveOut16Ex(session, space, offset, length, converted_buffer) else: return library.viMoveOut16(session, space, offset, length, converted_buffer) def move_out_32(library, session, space, offset, length, data, extended=False): """Moves an 32-bit block of data from local memory. Corresponds to viMoveOut32* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ converted_buffer = (ViUInt32 * length)(*tuple(data)) if extended: return library.viMoveOut32Ex(session, space, offset, length, converted_buffer) else: return library.viMoveOut32(session, space, offset, length, converted_buffer) def move_out_64(library, session, space, offset, length, data, extended=False): """Moves an 64-bit block of data from local memory. Corresponds to viMoveOut64* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ converted_buffer = (ViUInt64 * length)(*tuple(data)) if extended: return library.viMoveOut64Ex(session, space, offset, length, converted_buffer) else: return library.viMoveOut64(session, space, offset, length, converted_buffer) # noinspection PyShadowingBuiltins def open( library, 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. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ try: open_timeout = int(open_timeout) except ValueError: raise ValueError( "open_timeout (%r) must be an integer (or compatible type)" % open_timeout ) out_session = ViSession() # [ViSession, ViRsrc, ViAccessMode, ViUInt32, ViPSession] # ViRsrc converts from (str, unicode, bytes) to bytes ret = library.viOpen( session, resource_name, access_mode, open_timeout, byref(out_session) ) return out_session.value, ret def open_default_resource_manager(library): """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 constants.StatusCode Return value of the library call. """ session = ViSession() ret = library.viOpenDefaultRM(byref(session)) return session.value, ret def out_8(library, session, space, offset, data, extended=False): """Write an 8-bit value to the specified memory space and offset. Corresponds to viOut8* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ if extended: return library.viOut8Ex(session, space, offset, data) else: return library.viOut8(session, space, offset, data) def out_16(library, session, space, offset, data, extended=False): """Write a 16-bit value to the specified memory space and offset. Corresponds to viOut16* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ if extended: return library.viOut16Ex(session, space, offset, data, extended=False) else: return library.viOut16(session, space, offset, data, extended=False) def out_32(library, session, space, offset, data, extended=False): """Write a 32-bit value to the specified memory space and offset. Corresponds to viOut32* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ if extended: return library.viOut32Ex(session, space, offset, data) else: return library.viOut32(session, space, offset, data) def out_64(library, session, space, offset, data, extended=False): """Write a 64-bit value to the specified memory space and offset. Corresponds to viOut64* functions of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ if extended: return library.viOut64Ex(session, space, offset, data) else: return library.viOut64(session, space, offset, data) def parse_resource(library, session, resource_name): """Parse a resource string to get the interface information. Corresponds to viParseRsrc function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ interface_type = ViUInt16() interface_board_number = ViUInt16() # [ViSession, ViRsrc, ViPUInt16, ViPUInt16] # ViRsrc converts from (str, unicode, bytes) to bytes ret = library.viParseRsrc( session, resource_name, byref(interface_type), byref(interface_board_number) ) return ( ResourceInfo( constants.InterfaceType(interface_type.value), interface_board_number.value, None, None, None, ), ret, ) def parse_resource_extended(library, session, resource_name): """Parse a resource string to get extended interface information. Corresponds to viParseRsrcEx function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ interface_type = ViUInt16() interface_board_number = ViUInt16() resource_class = create_string_buffer(constants.VI_FIND_BUFLEN) unaliased_expanded_resource_name = create_string_buffer(constants.VI_FIND_BUFLEN) alias_if_exists = create_string_buffer(constants.VI_FIND_BUFLEN) # [ViSession, ViRsrc, ViPUInt16, ViPUInt16, ViAChar, ViAChar, ViAChar] # ViRsrc converts from (str, unicode, bytes) to bytes ret = library.viParseRsrcEx( session, resource_name, byref(interface_type), byref(interface_board_number), resource_class, unaliased_expanded_resource_name, alias_if_exists, ) res = [ buffer_to_text(val) for val in (resource_class, unaliased_expanded_resource_name, alias_if_exists) ] if res[-1] == "": res[-1] = None return ( ResourceInfo( constants.InterfaceType(interface_type.value), interface_board_number.value, *res ), ret, ) def peek_8(library, session, address): """Read an 8-bit value from the specified address. Corresponds to viPeek8 function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. Returns ------- int Data read from bus constants.StatusCode Return value of the library call. """ value_8 = ViUInt8() ret = library.viPeek8(session, address, byref(value_8)) return value_8.value, ret def peek_16(library, session, address): """Read an 16-bit value from the specified address. Corresponds to viPeek16 function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. Returns ------- int Data read from bus constants.StatusCode Return value of the library call. """ value_16 = ViUInt16() ret = library.viPeek16(session, address, byref(value_16)) return value_16.value, ret def peek_32(library, session, address): """Read an 32-bit value from the specified address. Corresponds to viPeek32 function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. Returns ------- int Data read from bus constants.StatusCode Return value of the library call. """ value_32 = ViUInt32() ret = library.viPeek32(session, address, byref(value_32)) return value_32.value, ret def peek_64(library, session, address): """Read an 64-bit value from the specified address. Corresponds to viPeek64 function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. Returns ------- int Data read from bus constants.StatusCode Return value of the library call. """ value_64 = ViUInt64() ret = library.viPeek64(session, address, byref(value_64)) return value_64.value, ret def poke_8(library, session, address, data): """Write an 8-bit value to the specified address. Corresponds to viPoke8 function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. data : int Data to write. Returns ------- constants.StatusCode Return value of the library call. """ return library.viPoke8(session, address, data) def poke_16(library, session, address, data): """Write an 16-bit value to the specified address. Corresponds to viPoke16 function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. data : int Data to write. Returns ------- constants.StatusCode Return value of the library call. """ return library.viPoke16(session, address, data) def poke_32(library, session, address, data): """Write an 32-bit value to the specified address. Corresponds to viPoke32 function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. data : int Data to write. Returns ------- constants.StatusCode Return value of the library call. """ return library.viPoke32(session, address, data) def poke_64(library, session, address, data): """Write an 64-bit value to the specified address. Corresponds to viPoke64 function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. address : VISAMemoryAddress Source address to read the value. data : int Data to write. Returns ------- constants.StatusCode Return value of the library call. """ return library.viPoke64(session, address, data) def read(library, session, count): """Reads data from device or interface synchronously. Corresponds to viRead function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. count : int Number of bytes to be read. Returns ------- bytes Date read constants.StatusCode Return value of the library call. """ buffer = create_string_buffer(count) return_count = ViUInt32() ret = library.viRead(session, buffer, count, byref(return_count)) return buffer.raw[: return_count.value], ret def read_stb(library, session): """Reads a status byte of the service request. Corresponds to viReadSTB function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. Returns ------- int Service request status byte constants.StatusCode Return value of the library call. """ status = ViUInt16() ret = library.viReadSTB(session, byref(status)) return status.value, ret def read_to_file(library, session, filename, count): """Read data synchronously, and store the transferred data in a file. Corresponds to viReadToFile function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ return_count = ViUInt32() ret = library.viReadToFile(session, filename, count, return_count) return return_count, ret def set_attribute(library, session, attribute, attribute_state): """Set the state of an attribute. Corresponds to viSetAttribute function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ return library.viSetAttribute(session, attribute, attribute_state) def set_buffer(library, session, mask, size): """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 ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ return library.viSetBuf(session, mask, size) def status_description(library, session, status): """Return a user-readable description of the status code passed to the operation. Corresponds to viStatusDesc function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. status : constants.StatusCode Status code to interpret. Returns ------- str User-readable string interpretation of the status code. constants.StatusCode Return value of the library call. """ description = create_string_buffer(256) ret = library.viStatusDesc(session, status, description) return buffer_to_text(description), ret def terminate(library, session, degree, job_id): """Request a VISA session to terminate normal execution of an operation. Corresponds to viTerminate function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ return library.viTerminate(session, degree, job_id) def uninstall_handler(library, session, event_type, handler, user_handle=None): """Uninstall handlers for events. Corresponds to viUninstallHandler function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ with set_user_handle_type(library, user_handle): if user_handle is not None: user_handle = byref(user_handle) return library.viUninstallHandler(session, event_type, handler, user_handle) def unlock(library, session): """Relinquish a lock for the specified resource. Corresponds to viUnlock function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. Returns ------- constants.StatusCode Return value of the library call. """ return library.viUnlock(session) def unmap_address(library, session): """Unmap memory space previously mapped by map_address(). Corresponds to viUnmapAddress function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. Returns ------- constants.StatusCode Return value of the library call. """ return library.viUnmapAddress(session) def unmap_trigger(library, session, trigger_source, trigger_destination): """Undo a previous map between a trigger source line and a destination line. Corresponds to viUnmapTrigger function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ return library.viUnmapTrigger(session, trigger_source, trigger_destination) def usb_control_in( library, session, request_type_bitmap_field, request_id, request_value, index, length=0, ): """Perform a USB control pipe transfer from the device. Corresponds to viUsbControlIn function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ buffer = create_string_buffer(length) return_count = ViUInt16() ret = library.viUsbControlIn( session, request_type_bitmap_field, request_id, request_value, index, length, buffer, byref(return_count), ) return buffer.raw[: return_count.value], ret def usb_control_out( library, session, request_type_bitmap_field, request_id, request_value, index, data="", ): """Perform a USB control pipe transfer to the device. Corresponds to viUsbControlOut function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 ------- constants.StatusCode Return value of the library call. """ length = len(data) return library.viUsbControlOut( session, request_type_bitmap_field, request_id, request_value, index, length, data, ) def vxi_command_query(library, session, mode, command): """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 ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ response = ViUInt32() ret = library.viVxiCommandQuery(session, mode, command, byref(response)) return response.value, ret def wait_on_event(library, session, in_event_type, timeout): """Wait for an occurrence of the specified event for a given session. Corresponds to viWaitOnEvent function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ out_event_type = ViEventType() out_context = ViEvent() ret = library.viWaitOnEvent( session, in_event_type, timeout, byref(out_event_type), byref(out_context) ) return out_event_type.value, out_context, ret def write(library, session, data): """Write data to device or interface synchronously. Corresponds to viWrite function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. data : bytes Data to be written. Returns ------- int Number of bytes actually transferred constants.StatusCode Return value of the library call. """ return_count = ViUInt32() # [ViSession, ViBuf, ViUInt32, ViPUInt32] ret = library.viWrite(session, data, len(data), byref(return_count)) return return_count.value, ret def write_asynchronously(library, session, data): """Write data to device or interface asynchronously. Corresponds to viWriteAsync function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. session : VISASession Unique logical identifier to a session. data : bytes Data to be written. Returns ------- VISAJobID Job ID of this asynchronous write operation constants.StatusCode Return value of the library call. """ job_id = ViJobId() # [ViSession, ViBuf, ViUInt32, ViPJobId] ret = library.viWriteAsync(session, data, len(data), byref(job_id)) return job_id, ret def write_from_file(library, session, filename, count): """Take data from a file and write it out synchronously. Corresponds to viWriteFromFile function of the VISA library. Parameters ---------- library : ctypes.WinDLL or ctypes.CDLL ctypes wrapped library. 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 constants.StatusCode Return value of the library call. """ return_count = ViUInt32() ret = library.viWriteFromFile(session, filename, count, return_count) return return_count, ret