Constants module
Provides user-friendly naming to values used in different functions.
- class pyvisa.constants.AccessModes(value)[source]
Whether and how to lock a resource when opening a connection.
- exclusive_lock = 1
Obtains a exclusive lock on the VISA resource.
- no_lock = 0
Does not obtain any lock on the VISA resource.
Obtains a lock on the VISA resouce which may be shared between multiple VISA sessions.
- class pyvisa.constants.StopBits(value)[source]
The number of stop bits that indicate the end of a frame on a serial resource.
Used only for ASRL resources.
- one = 10
- one_and_a_half = 15
- two = 20
- class pyvisa.constants.Parity(value)[source]
Parity type to use with every frame transmitted and received on a serial session.
Used only for ASRL resources.
- even = 2
- mark = 3
- none = 0
- odd = 1
- space = 4
- class pyvisa.constants.SerialTermination(value)[source]
The available methods for terminating a serial transfer.
- last_bit = 1
The transfer occurs with the last bit not set until the last character is sent.
- none = 0
The transfer terminates when all requested data is transferred or when an error occurs.
- termination_break = 3
The write transmits a break after all the characters for the write are sent.
- termination_char = 2
The transfer terminate by searching for “/” appending the termination character.
- class pyvisa.constants.InterfaceType(value)[source]
The hardware interface.
- asrl = 4
Serial devices connected to either an RS-232 or RS-485 controller.
- firewire = 9
Firewire device.
- gpib = 1
GPIB Interface.
- gpib_vxi = 3
GPIB VXI (VME eXtensions for Instrumentation).
- pxi = 5
PXI device.
- rio = 8
Rio device.
- rsnrp = 33024
Rohde and Schwarz Device via Passport
- tcpip = 6
TCPIP device.
- unknown = -1
- usb = 7
Universal Serial Bus (USB) hardware bus.
- vicp = 36000
Lecroy VICP via passport
- vxi = 2
VXI (VME eXtensions for Instrumentation), VME, MXI (Multisystem eXtension Interface).
- class pyvisa.constants.AddressState(value)[source]
State of a GPIB resource.
Corresponds to the Attribute.GPIB_address_state attribute
- listenr = 2
The resource is addressed to listen
- talker = 1
The resource is addressed to talk
- unaddressed = 0
The resource is unadressed
- class pyvisa.constants.IOProtocol(value)[source]
IO protocol used for communication.
See attributes.AttrVI_ATTR_IO_PROT for more details.
- fdc = 2
Fast data channel (FDC) protocol for VXI
- hs488 = 3
High speed 488 transfer for GPIB
- normal = 1
- protocol4882_strs = 4
488 style transfer for serial
- usbtmc_vendor = 5
Test measurement class vendor specific for USB
- class pyvisa.constants.LineState(value)[source]
State of a hardware line or signal.
The line for which the state can be queried are: - ASRC resource: BREAK, CTS, DCD, DSR, DTR, RI, RTS signals - GPIB resources: ATN, NDAC, REN, SRQ lines - VXI BACKPLANE: VXI/VME SYSFAIL backplane line
Search for LineState in attributes.py for more details.
- asserted = 1
The line/signal is currently asserted
- unasserted = 0
The line/signal is currently deasserted
- unknown = -1
The state of the line/signal is unknown
- class pyvisa.constants.StatusCode(value)[source]
Status codes that VISA driver-level operations can return.
- error_abort = -1073807312
The operation was aborted.
- error_allocation = -1073807300
Insufficient system resources to perform necessary memory allocation.
- error_attribute_read_only = -1073807329
The specified attribute is read-only.
- error_bus_error = -1073807304
Bus error occurred during transfer.
- error_closing_failed = -1073807338
Unable to deallocate the previously allocated data structures corresponding to this session or object reference.
- error_connection_lost = -1073807194
The connection for the specified session has been lost.
- error_file_access = -1073807199
An error occurred while trying to open the specified file. Possible causes include an invalid path or lack of access rights.
- error_file_i_o = -1073807198
An error occurred while performing I/O on the specified file.
- error_handler_not_installed = -1073807320
A handler is not currently installed for the specified event.
- error_in_progress = -1073807303
Unable to queue the asynchronous operation because there is already an operation in progress.
- error_input_protocol_violation = -1073807305
Device reported an input protocol error during transfer.
- error_interface_number_not_configured = -1073807195
The interface type is valid but the specified interface number is not configured.
- error_interrupt_pending = -1073807256
An interrupt is still pending from a previous call.
- error_invalid_access_key = -1073807327
The access key to the resource associated with this session is invalid.
- error_invalid_access_mode = -1073807341
Invalid access mode.
- error_invalid_address_space = -1073807282
Invalid address space specified.
- error_invalid_context = -1073807318
Specified event context is invalid.
- error_invalid_degree = -1073807333
Specified degree is invalid.
- error_invalid_event = -1073807322
Specified event type is not supported by the resource.
- error_invalid_expression = -1073807344
Invalid expression specified for search.
- error_invalid_format = -1073807297
A format specifier in the format string is invalid.
- error_invalid_handler_reference = -1073807319
The specified handler reference is invalid.
- error_invalid_job_i_d = -1073807332
Specified job identifier is invalid.
- error_invalid_length = -1073807229
Invalid length specified.
- error_invalid_line = -1073807200
The value specified by the line parameter is invalid.
- error_invalid_lock_type = -1073807328
The specified type of lock is not supported by this resource.
- error_invalid_mask = -1073807299
Invalid buffer mask specified.
- error_invalid_mechanism = -1073807321
Invalid mechanism specified.
- error_invalid_mode = -1073807215
The specified mode is invalid.
- error_invalid_object = -1073807346
The specified session or object reference is invalid.
- error_invalid_offset = -1073807279
Invalid offset specified.
- error_invalid_parameter = -1073807240
The value of an unknown parameter is invalid.
- error_invalid_protocol = -1073807239
The protocol specified is invalid.
- error_invalid_resource_name = -1073807342
Invalid resource reference specified. Parsing error.
- error_invalid_setup = -1073807302
Unable to start operation because setup is invalid due to inconsistent state of properties.
- error_invalid_size = -1073807237
Invalid size of window specified.
- error_invalid_width = -1073807278
Invalid source or destination width specified.
- error_io = -1073807298
Could not perform operation because of I/O error.
- error_library_not_found = -1073807202
A code library required by VISA could not be located or loaded.
- error_line_in_use = -1073807294
The specified trigger line is currently in use.
- error_machine_not_available = -1073807193
The remote machine does not exist or is not accepting any connections.
The device does not export any memory.
- error_no_listeners = -1073807265
No listeners condition is detected (both NRFD and NDAC are deasserted).
- error_no_permission = -1073807192
Access to the remote machine is denied.
- error_nonimplemented_operation = -1073807231
The specified operation is unimplemented.
- error_nonsupported_attribute = -1073807331
The specified attribute is not defined or supported by the referenced session, event, or find list.
- error_nonsupported_attribute_state = -1073807330
The specified state of the attribute is not valid or is not supported as defined by the session, event, or find list.
- error_nonsupported_format = -1073807295
A format specifier in the format string is not supported.
- error_nonsupported_interrupt = -1073807201
The interface cannot generate an interrupt on the requested level or with the requested statusID value.
- error_nonsupported_line = -1073807197
The specified trigger source line (trigSrc) or destination line (trigDest) is not supported by this VISA implementation, or the combination of lines is not a valid mapping.
- error_nonsupported_mechanism = -1073807196
The specified mechanism is not supported for the specified event type.
- error_nonsupported_mode = -1073807290
The specified mode is not supported by this VISA implementation.
- error_nonsupported_offset = -1073807276
Specified offset is not accessible from this hardware.
- error_nonsupported_offset_alignment = -1073807248
The specified offset is not properly aligned for the access width of the operation.
- error_nonsupported_operation = -1073807257
The session or object reference does not support this operation.
- error_nonsupported_varying_widths = -1073807275
Cannot support source and destination widths that are different.
- error_nonsupported_width = -1073807242
Specified width is not supported by this hardware.
- error_not_cic = -1073807264
The interface associated with this session is not currently the Controller-in-Charge.
- error_not_enabled = -1073807313
The session must be enabled for events of the specified type in order to receive them.
- error_not_system_controller = -1073807263
The interface associated with this session is not the system controller.
- error_output_protocol_violation = -1073807306
Device reported an output protocol error during transfer.
- error_queue_error = -1073807301
Unable to queue asynchronous operation.
- error_queue_overflow = -1073807315
The event queue for the specified type has overflowed, usually due to not closing previous events.
- error_raw_read_protocol_violation = -1073807307
Violation of raw read protocol occurred during transfer.
- error_raw_write_protocol_violation = -1073807308
Violation of raw write protocol occurred during transfer.
- error_resource_busy = -1073807246
The resource is valid, but VISA cannot currently access it.
- error_resource_locked = -1073807345
Specified type of lock cannot be obtained or specified operation cannot be performed because the resource is locked.
- error_resource_not_found = -1073807343
Insufficient location information, or the device or resource is not present in the system.
- error_response_pending = -1073807271
A previous response is still pending, causing a multiple query error.
- error_serial_framing = -1073807253
A framing error occurred during transfer.
- error_serial_overrun = -1073807252
An overrun error occurred during transfer. A character was not read from the hardware before the next character arrived.
- error_serial_parity = -1073807254
A parity error occurred during transfer.
- error_session_not_locked = -1073807204
The current session did not have any lock on the resource.
- error_srq_not_occurred = -1073807286
Service request has not been received for the session.
- error_system_error = -1073807360
Unknown system error.
- error_timeout = -1073807339
Timeout expired before operation completed.
- error_trigger_not_mapped = -1073807250
The path from the trigger source line (trigSrc) to the destination line (trigDest) is not currently mapped.
- error_user_buffer = -1073807247
A specified user buffer is not valid or cannot be accessed for the required size.
- error_window_already_mapped = -1073807232
The specified session currently contains a mapped window.
- error_window_not_mapped = -1073807273
The specified session is currently unmapped.
- success = 0
Operation completed successfully.
- success_device_not_present = 1073676413
Session opened successfully, but the device at the specified address is not responding.
- success_event_already_disabled = 1073676291
Specified event is already disabled for at least one of the specified mechanisms.
- success_event_already_enabled = 1073676290
Specified event is already enabled for at least one of the specified mechanisms.
- success_max_count_read = 1073676294
The number of bytes read is equal to the input count.
- success_nested_exclusive = 1073676442
Operation completed successfully, and this session has nested exclusive locks.
Operation completed successfully, and this session has nested shared locks.
- success_no_more_handler_calls_in_chain = 1073676440
Event handled successfully. Do not invoke any other handlers on this session for this event.
- success_queue_already_empty = 1073676292
Operation completed successfully, but the queue was already empty.
- success_queue_not_empty = 1073676416
Wait terminated successfully on receipt of an event notification. There is still at least one more event occurrence of the requested type(s) available for this session.
- success_synchronous = 1073676443
Asynchronous operation request was performed synchronously.
- success_termination_character_read = 1073676293
The specified termination character was read.
- success_trigger_already_mapped = 1073676414
The path from the trigger source line (trigSrc) to the destination line (trigDest) is already mapped.
- warning_configuration_not_loaded = 1073676407
The specified configuration either does not exist or could not be loaded. The VISA-specified defaults are used.
- warning_ext_function_not_implemented = 1073676457
The operation succeeded, but a lower level driver did not implement the extended functionality.
- warning_nonsupported_attribute_state = 1073676420
Although the specified state of the attribute is valid, it is not supported by this resource implementation.
- warning_nonsupported_buffer = 1073676424
The specified buffer is not supported.
- warning_null_object = 1073676418
The specified object reference is uninitialized.
- warning_queue_overflow = 1073676300
VISA received more event information of the specified type than the configured queue size could hold.
- warning_unknown_status = 1073676421
The status code passed to the operation could not be interpreted.