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# -*- coding: utf-8 -*-
"""GPIB Session implementation using linux-gpib or gpib-ctypes.
:copyright: 2015-2020 by PyVISA-py Authors, see AUTHORS for more details.
:license: MIT, see LICENSE for more details.
"""
import ctypes # Used for missing bindings not ideal
from bisect import bisect
from typing import Any, Iterator, List, Tuple, Union
from pyvisa import attributes, constants, logger
from pyvisa.constants import ResourceAttribute, StatusCode
from pyvisa.rname import GPIBInstr, GPIBIntfc
from .sessions import Session, UnknownAttribute
try:
GPIB_CTYPES = True
from gpib_ctypes import gpib # typing: ignore
from gpib_ctypes.Gpib import Gpib # typing: ignore
from gpib_ctypes.gpib.gpib import _lib as gpib_lib # typing: ignore
try:
# Add some extra binding not available by default
extra_funcs = [
("ibcac", [ctypes.c_int, ctypes.c_int], ctypes.c_int),
("ibgts", [ctypes.c_int, ctypes.c_int], ctypes.c_int),
("ibpct", [ctypes.c_int], ctypes.c_int),
]
for name, argtypes, restype in extra_funcs:
libfunction = gpib_lib[name]
libfunction.argtypes = argtypes
libfunction.restype = restype
except TypeError:
msg = (
"gpib_ctypes is installed but could not locate the gpib library.\n"
"Please manually load it using:\n"
" gpib_ctypes.gpib.gpib._load_lib(filename)\n"
"before importing pyvisa."
)
Session.register_unavailable(constants.InterfaceType.gpib, "INSTR", msg)
Session.register_unavailable(constants.InterfaceType.gpib, "INTFC", msg)
raise
except ImportError:
GPIB_CTYPES = False
try:
import gpib # typing: ignore
from Gpib import Gpib # typing: ignore
except ImportError as e:
msg = (
"Please install linux-gpib (Linux) or gpib-ctypes (Windows, Linux) "
"to use this resource type. Note that installing gpib-ctypes will "
"give you access to a broader range of functionalities.\n%s" % e
)
Session.register_unavailable(constants.InterfaceType.gpib, "INSTR", msg)
Session.register_unavailable(constants.InterfaceType.gpib, "INTFC", msg)
raise
# patch Gpib to avoid double closing of handles
def _patch_Gpib() -> None:
if not hasattr(Gpib, "close"):
_old_del = Gpib.__del__
def _inner(self):
_old_del(self)
self._own = False
Gpib.__del__ = _inner
Gpib.close = _inner
_patch_Gpib()
def _find_boards() -> Iterator[Tuple[int, int]]:
"""Find GPIB board addresses."""
for board in range(16):
try:
yield board, gpib.ask(board, 1)
except gpib.GpibError as e:
logger.debug("GPIB board %i error in _find_boards(): %s", board, repr(e))
def _find_listeners() -> Iterator[Tuple[int, int, int]]:
"""Find GPIB listeners."""
for board, boardpad in _find_boards():
for i in range(31):
j = 0
try:
if boardpad != i and gpib.listener(board, i):
yield board, i, j
elif boardpad != i:
for j in range(96, 126):
if gpib.listener(board, i, j):
yield board, i, j
except gpib.GpibError as e:
logger.debug(
"GPIB board %i paddr %i saddr %i error in _find_listeners(): %s",
board,
i,
j,
repr(e),
)
def _analyse_lines_value(value: int, line: int):
"""Determine the state of a GPIB line based on the iblines byte.
Parameters
----------
value : int
Value returned by iblines.
line : int
One of constants.VI_ATTR_GPIB_***_STATE where the *** can be REN, ATN,
NDAC, or SRQ
Returns
-------
constants.LineState
State of the line
StatusCode
Library StatusCode for the operation.
"""
if line == constants.VI_ATTR_GPIB_REN_STATE:
# REN bit valid = 0x10, REN bit value = 0x100
validity_mask = 0x10
value_mask = 0x100
elif line == constants.VI_ATTR_GPIB_ATN_STATE:
# ATN bit valid = 0x40, ATN bit value = 0x4000
validity_mask = 0x40
value_mask = 0x4000
elif line == constants.VI_ATTR_GPIB_NDAC_STATE:
# NDAC bit valid = 0x2, NDAC bit value = 0x200
validity_mask = 0x2
value_mask = 0x200
elif line == constants.VI_ATTR_GPIB_SRQ_STATE:
# SRQ bit valid = 0x20, SRQ bit value = 0x2000
validity_mask = 0x20
value_mask = 0x2000
if not value & validity_mask:
return constants.LineState.unknown, StatusCode.success
else:
if value & value_mask:
return constants.LineState.asserted, StatusCode.success
else:
return constants.LineState.unasserted, StatusCode.success
# linux-gpib timeout constants, in seconds. See GPIBSession._set_timeout.
TIMETABLE = (
0,
10e-6,
30e-6,
100e-6,
300e-6,
1e-3,
3e-3,
10e-3,
30e-3,
100e-3,
300e-3,
1.0,
3.0,
10.0,
30.0,
100.0,
300.0,
1000.0,
)
def convert_gpib_error(
error: gpib.GpibError, status: int, operation: str
) -> StatusCode:
"""Convert a GPIB error to a VISA StatusCode.
Parameters
----------
error : gpib.GpibError
Error to use to determine the proper status code.
status : int
Status byte of the GPIB library.
operation : str
Name of the operation that caused an exception. Used in logging.
Returns
-------
StatusCode
Status code matching the GPIB error.
"""
# First check the imeout condition in the status byte
if status & 0x4000:
return StatusCode.error_timeout
# All other cases are hard errors.
# In particular linux-gpib simply gives a string we could parse but that
# feels brittle. As a consequence we only try to be smart when using
# gpib-ctypes. However in both cases we log the exception at debug level.
else:
logger.debug("Failed to %s.", operation, exc_info=error)
if not GPIB_CTYPES:
return StatusCode.error_system_error
if error.code == 1:
return StatusCode.error_not_cic
elif error.code == 2:
return StatusCode.error_no_listeners
elif error.code == 4:
return StatusCode.error_invalid_mode
elif error.code == 11:
return StatusCode.error_nonsupported_operation
elif error.code == 1:
return StatusCode.error_not_cic
elif error.code == 21:
return StatusCode.error_resource_locked
else:
return StatusCode.error_system_error
def convert_gpib_status(status: int) -> StatusCode:
if status & 0x4000:
return StatusCode.error_timeout
elif status & 0x8000:
return StatusCode.error_system_error
else:
return StatusCode.success
class _GPIBCommon(Session):
"""Common base class for GPIB sessions.
Both INSTR and INTFC resources share the following attributes:
- VI_ATTR_INTF_TYPE
- VI_ATTR_TMO_VALUE
- VI_ATTR_INTF_INST_NAME
- VI_ATTR_INTF_NUM
- VI_ATTR_DMA_ALLOW_EN
- VI_ATTR_SEND_END_EN
- VI_ATTR_TERMCHAR
- VI_ATTR_TERM_CHAR_EN
- VI_ATTR_RD_BUF_OPER_MODE
- VI_ATTR_WR_BUF_OPER_MODE
- VI_ATTR_FILE_APPEND_EN
- VI_ATTR_GPIB_PRIMARY_ADDR
- VI_ATTR_GPIB_SECONDARY_ADDR
- VI_ATTR_GPIB_REN_STATE
"""
# Override parsed to take into account the fact that this class is only used
# for a specific kind of resource
parsed: Union[GPIBIntfc, GPIBInstr]
#: Bus wide controller.
controller: Gpib
@classmethod
def get_low_level_info(cls) -> str:
try:
ver = gpib.version()
except AttributeError:
ver = "< 4.0"
return "via Linux GPIB (%s)" % ver
def after_parsing(self) -> None:
minor = int(self.parsed.board)
# Secondary address (SAD) values should be in the range 96 to 126,
# 0 means the SAD is disabled.
sad = 0
timeout = 13
send_eoi = 1
eos_mode = 0
self.interface = None
if isinstance(self.parsed, GPIBInstr):
pad = int(self.parsed.primary_address)
if self.parsed.secondary_address is not None:
sad = int(self.parsed.secondary_address) + 0x60
# Used to talk to a specific resource
self.interface = Gpib(
name=minor,
pad=pad,
sad=sad,
timeout=timeout,
send_eoi=send_eoi,
eos_mode=eos_mode,
)
# Bus wide operation
self.controller = Gpib(name=minor)
# Force timeout setting to interface
self.set_attribute(
constants.ResourceAttribute.timeout_value,
attributes.AttributesByID[constants.VI_ATTR_TMO_VALUE].default,
)
for name in ("TERMCHAR", "TERMCHAR_EN"):
attribute = getattr(constants, "VI_ATTR_" + name)
self.attrs[attribute] = attributes.AttributesByID[attribute].default
def _get_timeout(
self, attribute: constants.ResourceAttribute
) -> Tuple[int, StatusCode]:
if self.interface:
# 0x3 is the hexadecimal reference to the IbaTMO (timeout) configuration
# option in linux-gpib.
gpib_timeout = self.interface.ask(3)
if gpib_timeout and gpib_timeout < len(TIMETABLE):
self.timeout = TIMETABLE[gpib_timeout]
else:
# value is 0 or out of range -> infinite
self.timeout = None
return super(_GPIBCommon, self)._get_timeout(attribute)
def _set_timeout(self, attribute: constants.ResourceAttribute, value: int):
"""Set the timeout value.
linux-gpib only supports 18 discrete timeout values. If a timeout
value other than these is requested, it will be rounded up to the closest
available value. Values greater than the largest available timout value
will instead be rounded down. The available timeout values are:
0 Never timeout.
1 10 microseconds
2 30 microseconds
3 100 microseconds
4 300 microseconds
5 1 millisecond
6 3 milliseconds
7 10 milliseconds
8 30 milliseconds
9 100 milliseconds
10 300 milliseconds
11 1 second
12 3 seconds
13 10 seconds
14 30 seconds
15 100 seconds
16 300 seconds
17 1000 seconds
"""
status = super(_GPIBCommon, self)._set_timeout(attribute, value)
# Inspect the result of setting the value to decide how to translate the result
# on the interface.
if self.interface:
if self.timeout is None:
gpib_timeout = 0
else:
# round up only values that are higher by 0.1% than discrete values
gpib_timeout = min(bisect(TIMETABLE, 0.999 * self.timeout), 17)
self.timeout = TIMETABLE[gpib_timeout]
self.interface.timeout(gpib_timeout)
return status
def close(self) -> StatusCode:
if self.interface:
self.interface.close()
self.controller.close()
return StatusCode.success
def read(self, count: int) -> Tuple[bytes, StatusCode]:
"""Reads data from device or interface synchronously.
Corresponds to viRead function of the VISA library.
Parameters
----------
count : int
Number of bytes to be read.
Returns
-------
bytes
Data read from the interface.
StatusCode
Return value of the library call.
"""
# INTFC don't have an interface so use the controller
ifc = self.interface or self.controller
# END 0x2000
checker = lambda current: ifc.ibsta() & 0x2000 # noqa: E731
reader = lambda: ifc.read(count) # noqa: E731
return self._read(reader, count, checker, False, None, False, gpib.GpibError)
def write(self, data: bytes) -> Tuple[int, StatusCode]:
"""Writes data to device or interface synchronously.
Corresponds to viWrite function of the VISA library.
Parameters
----------
data : bytes
Data to be written.
Returns
-------
int
Number of bytes actually transferred
StatusCode
Return value of the library call.
"""
logger.debug("GPIB.write %r" % data)
# INTFC don't have an interface so use the controller
ifc = self.interface or self.controller
try:
ifc.write(data)
count = ifc.ibcnt() # number of bytes transmitted
return count, StatusCode.success
except gpib.GpibError as e:
return 0, convert_gpib_error(e, ifc.ibsta(), "write")
def gpib_control_ren(self, mode: constants.RENLineOperation) -> StatusCode:
"""Controls the state of the GPIB Remote Enable (REN) interface line.
Optionally the remote/local state of the device is also controlled.
Corresponds to viGpibControlREN function of the VISA library.
Parameters
----------
mode : constants.RENLineOperation
Specifies the state of the REN line and optionally the device
remote/local state.
Returns
-------
StatusCode
Return value of the library call.
"""
if isinstance(self.parsed, GPIBIntfc):
if mode not in (
constants.VI_GPIB_REN_ASSERT,
constants.VI_GPIB_REN_DEASSERT,
constants.VI_GPIB_REN_ASSERT_LLO,
):
return constants.StatusCode.error_nonsupported_operation
# INTFC don't have an interface so use the controller
ifc = self.interface or self.controller
try:
if mode == constants.VI_GPIB_REN_DEASSERT_GTL:
# Send GTL command byte (cf linux-gpib documentation)
ifc.command(chr(1))
if mode in (
constants.VI_GPIB_REN_DEASSERT,
constants.VI_GPIB_REN_DEASSERT_GTL,
):
self.controller.remote_enable(0)
if mode == constants.VI_GPIB_REN_ASSERT_LLO:
# LLO
ifc.command(b"0x11")
elif mode == constants.VI_GPIB_REN_ADDRESS_GTL:
# GTL
ifc.command(b"0x1")
elif mode == constants.VI_GPIB_REN_ASSERT_ADDRESS_LLO:
pass
elif mode in (
constants.VI_GPIB_REN_ASSERT,
constants.VI_GPIB_REN_ASSERT_ADDRESS,
):
ifc.remote_enable(1)
if (
isinstance(self.parsed, GPIBInstr)
and mode == constants.VI_GPIB_REN_ASSERT_ADDRESS
):
# 0 for the secondary address means don't use it
ifc.listener(
self.parsed.primary_address, self.parsed.secondary_address
)
except gpib.GpibError as e:
return convert_gpib_error(e, self.interface.ibsta(), "perform control REN")
return constants.StatusCode.success
def _get_attribute(self, attribute: ResourceAttribute) -> Tuple[Any, StatusCode]:
"""Get the value for a given VISA attribute for this session.
Use to implement custom logic for attributes.
Parameters
----------
attribute : ResourceAttribute
Attribute for which the state query is made
Returns
-------
Any
The state of the queried attribute for a specified resource
StatusCode
Return value of the library call.
"""
# TODO implement the following attributes
# - VI_ATTR_INTF_INST_NAME RO
# - VI_ATTR_DMA_ALLOW_EN RW
# - VI_ATTR_RD_BUF_OPER_MODE RW
# - VI_ATTR_WR_BUF_OPER_MODE RW
# - VI_ATTR_FILE_APPEND_EN RW
# INTFC don't have an interface so use the controller
ifc = self.interface or self.controller
if attribute == ResourceAttribute.gpib_primary_address:
# IbaPAD 0x1
return ifc.ask(1), StatusCode.success
elif attribute == ResourceAttribute.gpib_secondary_address:
# IbaSAD 0x2
# Remove 0x60 because National Instruments.
_ = ifc.ask(2)
if ifc.ask(2):
return ifc.ask(2) - 96, StatusCode.success
else:
return constants.VI_NO_SEC_ADDR, StatusCode.success
elif attribute == ResourceAttribute.gpib_ren_state:
try:
lines = self.controller.lines()
return _analyse_lines_value(lines, attribute)
except AttributeError:
# some versions of linux-gpib do not expose Gpib.lines()
return constants.VI_STATE_UNKNOWN, StatusCode.success
elif attribute == ResourceAttribute.send_end_enabled:
# Do not use IbaEndBitIsNormal 0x1a which relates to EOI on read()
# not write(). see issue #196
# IbcEOT 0x4
if ifc.ask(4):
return constants.VI_TRUE, StatusCode.success
else:
return constants.VI_FALSE, StatusCode.success
elif attribute == ResourceAttribute.interface_number:
# IbaBNA 0x200
return ifc.ask(512), StatusCode.success
elif attribute == ResourceAttribute.interface_type:
return constants.InterfaceType.gpib, StatusCode.success
raise UnknownAttribute(attribute)
def _set_attribute(
self, attribute: constants.ResourceAttribute, attribute_state: Any
) -> StatusCode:
"""Sets the state of an attribute.
Corresponds to viSetAttribute function of the VISA library.
Parameters
----------
attribute : constants.ResourceAttribute
Attribute for which the state is to be modified. (Attributes.*)
attribute_state : Any
The state of the attribute to be set for the specified object.
Returns
-------
StatusCode
Return value of the library call.
"""
# TODO implement the following attributes
# - VI_ATTR_DMA_ALLOW_EN RW
# - VI_ATTR_RD_BUF_OPER_MODE RW
# - VI_ATTR_WR_BUF_OPER_MODE RW
# - VI_ATTR_FILE_APPEND_EN RW
# INTFC don't have an interface so use the controller
ifc = self.interface or self.controller
if attribute == ResourceAttribute.gpib_readdress_enabled:
# IbcREADDR 0x6
# Setting has no effect in linux-gpib.
if isinstance(attribute_state, int):
ifc.config(6, attribute_state)
return StatusCode.success
else:
return StatusCode.error_nonsupported_attribute_state
elif attribute == ResourceAttribute.gpib_primary_address:
# IbcPAD 0x1
if isinstance(attribute_state, int) and 0 <= attribute_state <= 30:
ifc.config(1, attribute_state)
return StatusCode.success
else:
return StatusCode.error_nonsupported_attribute_state
elif attribute == ResourceAttribute.gpib_secondary_address:
# IbcSAD 0x2
# Add 0x60 because National Instruments.
if isinstance(attribute_state, int) and 0 <= attribute_state <= 30:
if ifc.ask(2):
ifc.config(2, attribute_state + 96)
return StatusCode.success
else:
return StatusCode.error_nonsupported_attribute
else:
return StatusCode.error_nonsupported_attribute_state
elif attribute == ResourceAttribute.gpib_unadress_enable:
# IbcUnAddr 0x1b
try:
ifc.config(27, attribute_state)
return StatusCode.success
except gpib.GpibError:
return StatusCode.error_nonsupported_attribute_state
elif attribute == ResourceAttribute.send_end_enabled:
# Do not use IbaEndBitIsNormal 0x1a which relates to EOI on read()
# not write(). see issue #196
# IbcEOT 0x4
if isinstance(attribute_state, int):
ifc.config(4, attribute_state)
return StatusCode.success
else:
return StatusCode.error_nonsupported_attribute_state
raise UnknownAttribute(attribute)
# TODO: Check secondary addresses.
@Session.register(constants.InterfaceType.gpib, "INSTR")
class GPIBSession(_GPIBCommon):
"""A GPIB Session that uses linux-gpib to do the low level communication."""
# Override parsed to take into account the fact that this class is only used
# for a specific kind of resource
parsed: GPIBInstr
@staticmethod
def list_resources() -> List[str]:
return [
"GPIB%d::%d::INSTR" % (board, pad)
if sad == 0
else "GPIB%d::%d::%d::INSTR" % (board, pad, sad - 0x60)
for board, pad, sad in _find_listeners()
]
def clear(self) -> StatusCode:
"""Clears a device.
Corresponds to viClear function of the VISA library.
Returns
-------
StatusCode
Return value of the library call.
"""
logger.debug("GPIB.device clear")
try:
self.interface.clear()
return StatusCode.success
except gpib.GpibError as e:
return convert_gpib_error(e, self.interface.ibsta(), "clear")
def assert_trigger(self, protocol: constants.TriggerProtocol) -> StatusCode:
"""Asserts hardware trigger.
Parameters
----------
protocol : constants.TriggerProtocol
Triggering protocol to use.
Only supports constants.TriggerProtocol.default
Returns
-------
StatusCode
Return value of the library call.
"""
logger.debug("GPIB.device assert hardware trigger")
try:
if protocol == constants.VI_TRIG_PROT_DEFAULT:
self.interface.trigger()
return StatusCode.success
else:
return StatusCode.error_nonsupported_operation
except gpib.GpibError as e:
return convert_gpib_error(e, self.interface.ibsta(), "assert trigger")
def read_stb(self) -> Tuple[int, StatusCode]:
"""Read the device status byte."""
try:
return self.interface.serial_poll(), StatusCode.success
except gpib.GpibError as e:
return 0, convert_gpib_error(e, self.interface.ibsta(), "read STB")
def _get_attribute(
self, attribute: constants.ResourceAttribute
) -> Tuple[Any, StatusCode]:
"""Get the value for a given VISA attribute for this session.
Use to implement custom logic for attributes. GPIB::INSTR have the
following specific attributes:
- VI_ATTR_TRIG_ID
- VI_ATTR_IO_PROT
- VI_ATTR_SUPPRESS_END_EN
- VI_ATTR_GPIB_READDR_EN
- VI_ATTR_GPIB_UNADDR_EN
Parameters
----------
attribute : constants.ResourceAttribute
Resource attribute for which the state query is made
Returns
-------
Any
State of the queried attribute for a specified resource
StatusCode
Return value of the library call.
"""
# TODO implement the following attributes
# - VI_ATTR_TRIG_ID RW or RO see specs
# - VI_ATTR_IO_PROT RW
# - VI_ATTR_SUPPRESS_END_EN RW
ifc = self.interface
if attribute == constants.VI_ATTR_GPIB_READDR_EN:
# IbaREADDR 0x6
# Setting has no effect in linux-gpib.
return ifc.ask(6), StatusCode.success
elif attribute == constants.VI_ATTR_GPIB_UNADDR_EN:
# IbaUnAddr 0x1b
if ifc.ask(27):
return constants.VI_TRUE, StatusCode.success
else:
return constants.VI_FALSE, StatusCode.success
return super(GPIBSession, self)._get_attribute(attribute)
def _set_attribute(
self, attribute: ResourceAttribute, attribute_state: Any
) -> StatusCode:
"""Sets the state of an attribute.
Corresponds to viSetAttribute function of the VISA library.
Parameters
----------
attribute : ResourceAttribute
Attribute for which the state is to be modified. (Attributes.*)
attribute_state : Any
The state of the attribute to be set for the specified object.
Returns
-------
StatusCode
Return value of the library call.
"""
# TODO implement the following attributes
# - VI_ATTR_TRIG_ID RW or RO see specs
# - VI_ATTR_IO_PROT RW
# - VI_ATTR_SUPPRESS_END_EN RW
ifc = self.interface
if attribute == constants.VI_ATTR_GPIB_READDR_EN:
# IbcREADDR 0x6
# Setting has no effect in linux-gpib.
if isinstance(attribute_state, int):
ifc.config(6, attribute_state)
return StatusCode.success
else:
return StatusCode.error_nonsupported_attribute_state
elif attribute == constants.VI_ATTR_GPIB_UNADDR_EN:
# IbcUnAddr 0x1b
try:
ifc.config(27, attribute_state)
return StatusCode.success
except gpib.GpibError:
return StatusCode.error_nonsupported_attribute_state
return super(GPIBSession, self)._set_attribute(attribute, attribute_state)
@Session.register(constants.InterfaceType.gpib, "INTFC")
class GPIBInterface(_GPIBCommon):
"""A GPIB Interface that uses linux-gpib to do the low level communication."""
# Override parsed to take into account the fact that this class is only used
# for a specific kind of resource
parsed: GPIBIntfc
@staticmethod
def list_resources() -> List[str]:
return ["GPIB%d::INTFC" % board for board, pad in _find_boards()]
def gpib_command(self, command_bytes: bytes) -> Tuple[int, StatusCode]:
"""Write GPIB command byte on the bus.
Corresponds to viGpibCommand function of the VISA library.
See: https://linux-gpib.sourceforge.io/doc_html/gpib-protocol.html#REFERENCE-COMMAND-BYTES
Parameters
----------
command_bytes : bytes
Command bytes to send
Returns
-------
int
Number of written bytes,
StatusCode
Return value of the library call.
"""
try:
return self.controller.command(command_bytes), StatusCode.success
except gpib.GpibError as e:
return 0, convert_gpib_error(e, self.controller.ibsta(), "gpib command")
def gpib_send_ifc(self) -> StatusCode:
"""Pulse the interface clear line (IFC) for at least 100 microseconds.
Corresponds to viGpibSendIFC function of the VISA library.
"""
logger.debug("GPIB.interface clear")
try:
self.controller.interface_clear()
return StatusCode.success
except gpib.GpibError as e:
return convert_gpib_error(e, self.controller.ibsta(), "send IFC")
def gpib_control_atn(self, mode: constants.ATNLineOperation) -> StatusCode:
"""Specifies the state of the ATN line and the local active controller state.
Corresponds to viGpibControlATN function of the VISA library.
Parameters
----------
mode : constants.ATNLineOperation
Specifies the state of the ATN line and optionally the local active
controller state.
Returns
-------
StatusCode
Return value of the library call.
"""
logger.debug("GPIB.control atn")
if mode == constants.VI_GPIB_ATN_ASSERT:
status = gpib_lib.ibcac(self.controller.id, 0)
elif mode == constants.VI_GPIB_ATN_DEASSERT:
status = gpib_lib.ibgts(self.controller.id, 0)
elif mode == constants.VI_GPIB_ATN_ASSERT_IMMEDIATE:
# Asynchronous assertion (the name is counter intuitive)
status = gpib_lib.ibcac(self.controller.id, 1)
elif mode == constants.VI_GPIB_ATN_DEASSERT_HANDSHAKE:
status = gpib_lib.ibgts(self.controller.id, 1)
else:
return constants.StatusCode.error_invalid_mode
return convert_gpib_status(status)
def gpib_pass_control(
self, primary_address: int, secondary_address: int
) -> StatusCode:
"""Tell a GPIB device to become controller in charge (CIC).
Corresponds to viGpibPassControl function of the VISA library.
Parameters
----------
primary_address : int
Primary address of the GPIB device to which you want to pass control.
secondary_address : int
Secondary address of the targeted GPIB device.
If the targeted device does not have a secondary address,
this parameter should contain the value Constants.VI_NO_SEC_ADDR.
Returns
-------
StatusCode
Return value of the library call.
"""
# ibpct need to get the device id matching the primary and secondary address
logger.debug("GPIB.pass control")
try:
did = gpib.dev(self.parsed.board, primary_address, secondary_address)
except gpib.GpibError:
logger.exception(
"Failed to get id for %s, %d", primary_address, secondary_address
)
return StatusCode.error_resource_not_found
status = gpib_lib.ibpct(did)
return convert_gpib_status(status)
def _get_attribute(self, attribute: ResourceAttribute) -> Tuple[Any, StatusCode]:
"""Get the value for a given VISA attribute for this session.
Use to implement custom logic for attributes. GPIB::INTFC have the
following specific attributes:
- VI_ATTR_DEV_STATUS_BYTE
- VI_ATTR_GPIB_ATN_STATE
- VI_ATTR_GPIB_NDAC_STATE
- VI_ATTR_GPIB_SRQ_STATE
- VI_ATTR_GPIB_CIC_STATE
- VI_ATTR_GPIB_SYS_CNTRL_STATE
- VI_ATTR_GPIB_HS488_CBL_LEN
- VI_ATTR_GPIB_ADDR_STATE
Parameters
----------
attribute: ResourceAttribute
Resource attribute for which the state query is made.
Returns
-------
Any
The state of the queried attribute for a specified resource,
StatusCode
Return value of the library call.
"""
# TODO implement the following attributes
# - VI_ATTR_DEV_STATUS_BYTE RW
# - VI_ATTR_GPIB_SYS_CNTRL_STATE RW
# - VI_ATTR_GPIB_HS488_CBL_LEN RO
# - VI_ATTR_GPIB_ADDR_STATE RO
ifc = self.controller
if attribute == constants.VI_ATTR_GPIB_CIC_STATE:
# ibsta CIC = 0x0020
if ifc.ibsta() & 0x0020:
return constants.VI_TRUE, StatusCode.success
else:
return constants.VI_FALSE, StatusCode.success
elif attribute in (
constants.VI_ATTR_GPIB_ATN_STATE,
constants.VI_ATTR_GPIB_NDAC_STATE,
constants.VI_ATTR_GPIB_SRQ_STATE,
):
try:
lines = ifc.lines()
return _analyse_lines_value(lines, attribute)
except AttributeError:
# some versions of linux-gpib do not expose Gpib.lines()
return constants.VI_STATE_UNKNOWN, StatusCode.success
return super()._get_attribute(attribute)
def _set_attribute(
self, attribute: ResourceAttribute, attribute_state: Any
) -> StatusCode:
"""Sets the state of an attribute.
Corresponds to viSetAttribute function of the VISA library.
Parameters
----------
attribute : ResourceAttribute
Attribute for which the state is to be modified.
attribute_state : Any
The state of the attribute to be set for the specified object.
Returns
-------
StatusCode
Return value of the library call.
"""
# TODO implement the following attributes
# - VI_ATTR_GPIB_SYS_CNTRL_STATE
# - VI_ATTR_DEV_STATUS_BYTE
# INTFC don't have an interface so use the controller
_ = self.controller
return super()._set_attribute(attribute, attribute_state)
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