Constants module

Provides user-friendly naming to values used in different functions.

class pyvisa.constants.AccessModes

exclusive_lock = None

Obtains a exclusive lock on the VISA resource.

no_lock = None

Does not obtain any lock on the VISA resource.

shared_lock = None

Obtains a lock on the VISA resouce which may be shared between multiple VISA sessions.

class pyvisa.constants.StopBits

The number of stop bits that indicate the end of a frame.

class pyvisa.constants.Parity

The parity types to use with every frame transmitted and received on a serial session.

class pyvisa.constants.SerialTermination

The available methods for terminating a serial transfer.

last_bit = None

The transfer occurs with the last bit not set until the last character is sent.

none = None

The transfer terminates when all requested data is transferred or when an error occurs.

termination_break = None

The write transmits a break after all the characters for the write are sent.

termination_char = None

The transfer terminate by searching for “/” appending the termination character.

class pyvisa.constants.InterfaceType

The hardware interface

asrl = None

Serial devices connected to either an RS-232 or RS-485 controller.

firewire = None

Firewire device.

gpib = None

GPIB Interface.

gpib_vxi = None

GPIB VXI (VME eXtensions for Instrumentation).

pxi = None

PXI device.

rio = None

Rio device.

rsnrp = None

Rohde and Schwarz Device via Passport

tcpip = None

TCPIP device.

usb = None

Universal Serial Bus (USB) hardware bus.

vxi = None

VXI (VME eXtensions for Instrumentation), VME, MXI (Multisystem eXtension Interface).

class pyvisa.constants.AddressState

class pyvisa.constants.IOProtocol

fdc = None

Fast data channel (FDC) protocol for VXI

hs488 = None

High speed 488 transfer for GPIB

protocol4882_strs = None

488 style transfer for serial

usbtmc_vendor = None

Test measurement class vendor specific for USB

class pyvisa.constants.LineState

class pyvisa.constants.StatusCode

Specifies the status codes that NI-VISA driver-level operations can return.

error_abort = None

The operation was aborted.

error_allocation = None

Insufficient system resources to perform necessary memory allocation.

error_attribute_read_only = None

The specified attribute is read-only.

error_bus_error = None

Bus error occurred during transfer.

error_closing_failed = None

Unable to deallocate the previously allocated data structures corresponding to this session or object reference.

error_connection_lost = None

The connection for the specified session has been lost.

error_file_access = None

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 = None

An error occurred while performing I/O on the specified file.

error_handler_not_installed = None

A handler is not currently installed for the specified event.

error_in_progress = None

Unable to queue the asynchronous operation because there is already an operation in progress.

error_input_protocol_violation = None

Device reported an input protocol error during transfer.

error_interface_number_not_configured = None

The interface type is valid but the specified interface number is not configured.

error_interrupt_pending = None

An interrupt is still pending from a previous call.

error_invalid_access_key = None

The access key to the resource associated with this session is invalid.

error_invalid_access_mode = None

Invalid access mode.

error_invalid_address_space = None

Invalid address space specified.

error_invalid_context = None

Specified event context is invalid.

error_invalid_degree = None

Specified degree is invalid.

error_invalid_event = None

Specified event type is not supported by the resource.

error_invalid_expression = None

Invalid expression specified for search.

error_invalid_format = None

A format specifier in the format string is invalid.

error_invalid_handler_reference = None

The specified handler reference is invalid.

error_invalid_job_i_d = None

Specified job identifier is invalid.

error_invalid_length = None

Invalid length specified.

error_invalid_line = None

The value specified by the line parameter is invalid.

error_invalid_lock_type = None

The specified type of lock is not supported by this resource.

error_invalid_mask = None

Invalid buffer mask specified.

error_invalid_mechanism = None

Invalid mechanism specified.

error_invalid_mode = None

The specified mode is invalid.

error_invalid_object = None

The specified session or object reference is invalid.

error_invalid_offset = None

Invalid offset specified.

error_invalid_parameter = None

The value of an unknown parameter is invalid.

error_invalid_protocol = None

The protocol specified is invalid.

error_invalid_resource_name = None

Invalid resource reference specified. Parsing error.

error_invalid_setup = None

Unable to start operation because setup is invalid due to inconsistent state of properties.

error_invalid_size = None

Invalid size of window specified.

error_invalid_width = None

Invalid source or destination width specified.

error_io = None

Could not perform operation because of I/O error.

error_library_not_found = None

A code library required by VISA could not be located or loaded.

error_line_in_use = None

The specified trigger line is currently in use.

error_machine_not_available = None

The remote machine does not exist or is not accepting any connections.

error_memory_not_shared = None

The device does not export any memory.

error_no_listeners = None

No listeners condition is detected (both NRFD and NDAC are deasserted).

error_no_permission = None

Access to the remote machine is denied.

error_nonimplemented_operation = None

The specified operation is unimplemented.

error_nonsupported_attribute = None

The specified attribute is not defined or supported by the referenced session, event, or find list.

error_nonsupported_attribute_state = None

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 = None

A format specifier in the format string is not supported.

error_nonsupported_interrupt = None

The interface cannot generate an interrupt on the requested level or with the requested statusID value.

error_nonsupported_line = None

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 = None

The specified mechanism is not supported for the specified event type.

error_nonsupported_mode = None

The specified mode is not supported by this VISA implementation.

error_nonsupported_offset = None

Specified offset is not accessible from this hardware.

error_nonsupported_offset_alignment = None

The specified offset is not properly aligned for the access width of the operation.

error_nonsupported_operation = None

The session or object reference does not support this operation.

error_nonsupported_varying_widths = None

Cannot support source and destination widths that are different.

error_nonsupported_width = None

Specified width is not supported by this hardware.

error_not_cic = None

The interface associated with this session is not currently the Controller-in-Charge.

error_not_enabled = None

The session must be enabled for events of the specified type in order to receive them.

error_not_system_controller = None

The interface associated with this session is not the system controller.

error_output_protocol_violation = None

Device reported an output protocol error during transfer.

error_queue_error = None

Unable to queue asynchronous operation.

error_queue_overflow = None

The event queue for the specified type has overflowed, usually due to not closing previous events.

error_raw_read_protocol_violation = None

Violation of raw read protocol occurred during transfer.

error_raw_write_protocol_violation = None

Violation of raw write protocol occurred during transfer.

error_resource_busy = None

The resource is valid, but VISA cannot currently access it.

error_resource_locked = None

Specified type of lock cannot be obtained or specified operation cannot be performed because the resource is locked.

error_resource_not_found = None

Insufficient location information, or the device or resource is not present in the system.

error_response_pending = None

A previous response is still pending, causing a multiple query error.

error_serial_framing = None

A framing error occurred during transfer.

error_serial_overrun = None

An overrun error occurred during transfer. A character was not read from the hardware before the next character arrived.

error_serial_parity = None

A parity error occurred during transfer.

error_session_not_locked = None

The current session did not have any lock on the resource.

error_srq_not_occurred = None

Service request has not been received for the session.

error_system_error = None

Unknown system error.

error_timeout = None

Timeout expired before operation completed.

error_trigger_not_mapped = None

The path from the trigger source line (trigSrc) to the destination line (trigDest) is not currently mapped.

error_user_buffer = None

A specified user buffer is not valid or cannot be accessed for the required size.

error_window_already_mapped = None

The specified session currently contains a mapped window.

error_window_not_mapped = None

The specified session is currently unmapped.

success = None

Operation completed successfully.

success_device_not_present = None

Session opened successfully, but the device at the specified address is not responding.

success_event_already_disabled = None

Specified event is already disabled for at least one of the specified mechanisms.

success_event_already_enabled = None

Specified event is already enabled for at least one of the specified mechanisms.

success_max_count_read = None

The number of bytes read is equal to the input count.

success_nested_exclusive = None

Operation completed successfully, and this session has nested exclusive locks.

success_nested_shared = None

Operation completed successfully, and this session has nested shared locks.

success_no_more_handler_calls_in_chain = None

Event handled successfully. Do not invoke any other handlers on this session for this event.

success_queue_already_empty = None

Operation completed successfully, but the queue was already empty.

success_queue_not_empty = None

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_syncronous = None

Asynchronous operation request was performed synchronously.

success_termination_character_read = None

The specified termination character was read.

success_trigger_already_mapped = None

The path from the trigger source line (trigSrc) to the destination line (trigDest) is already mapped.

warning_configuration_not_loaded = None

The specified configuration either does not exist or could not be loaded. The VISA-specified defaults are used.

warning_ext_function_not_implemented = None

The operation succeeded, but a lower level driver did not implement the extended functionality.

warning_nonsupported_attribute_state = None

Although the specified state of the attribute is valid, it is not supported by this resource implementation.

warning_nonsupported_buffer = None

The specified buffer is not supported.

warning_null_object = None

The specified object reference is uninitialized.

warning_queue_overflow = None

VISA received more event information of the specified type than the configured queue size could hold.

warning_unknown_status = None

The status code passed to the operation could not be interpreted.