"""
Utility and base class related to visa
This library depends on `pyvisa <https://pyvisa.readthedocs.io/>`_ for VISA control.
"""
from typing import Dict, Optional
import os
import re
from dataclasses import dataclass
from logging import getLogger
import pyvisa
logger = getLogger(__name__)
@dataclass
class _VisaManagerDevice:
idn: str
inst: pyvisa.Resource
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class VisaManager:
"""
Manager class of visa device based on pyvisa module
Do not intialize directory, use :py:meth:`get_visa_manager() <ebilab.experiment.devices.visa.get_visa_manager>` method instead.
"""
_rm: Optional[pyvisa.ResourceManager] = None
_devices: Dict[str, _VisaManagerDevice] = {}
@property
def rm(self):
"""
ResourceManager of pyvisa module
"""
return self._rm
def __del__(self):
for _, device in self._devices.items():
device.inst.close()
if self.rm:
self.rm.close()
def __init__(self):
logger.debug(f"Initializing VisaManager")
os.add_dll_directory('C:\\Program Files\\Keysight\\IO Libraries Suite\\bin') # omajinai
rm = pyvisa.ResourceManager()
logger.info(f"Resource manager initialized: {str(rm)}")
visa_list = rm.list_resources()
logger.debug(f"List resources: {str(visa_list)}")
for addr in visa_list:
try:
inst = rm.open_resource(addr)
try:
idn = inst.query('*IDN?')
logger.debug(f"*IDN? to {addr}: {idn}")
self._devices[addr] = _VisaManagerDevice(idn, inst)
except:
logger.debug(f"No response to *IDN? from {addr}")
inst.close()
except:
pass
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def get_inst(self, pattern: str) -> Optional[pyvisa.Resource]:
"""
Get pyvisa instance from pattern that matches *IDN? result.
Args:
pattern (str): regex pattern
Returns:
pyvisa Resource
"""
for addr, device in self._devices.items():
if re.search(pattern, device.idn):
logger.info(f"{device.idn} ({addr}) matched {pattern}")
return device.inst
return None
# To be singleton
_visa_manager = None
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def get_visa_manager():
"""
Function to get :py:class:`VisaManager <ebilab.experiment.devices.visa.VisaManager>` class.
Many times of call of this function returns same VisaManager.
Returns:
VisaManager class
"""
global _visa_manager
if _visa_manager is None:
_visa_manager = VisaManager()
return _visa_manager
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class DeviceNotFoundError(Exception):
pass
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class VisaDevice:
"""
Base class of visa device.
You can inherit this class and implement class to new device.
Attributes:
pyvisa_inst: instance from `ResourceManager.open_resource` of pyvisa module
Please use this only when you use method which is not supported in VisaDevice class
"""
_idn_pattern: Optional[str] = None
def __init__(self, *, addr: str = None, **kwargs):
if self._idn_pattern is None:
raise NotImplementedError("idn_pattern is None")
inst = get_visa_manager().get_inst(self._idn_pattern)
if inst is None:
raise DeviceNotFoundError(f"Device matching \"{self._idn_pattern}\" is not found")
self.pyvisa_inst = inst
self.pyvisa_inst.timeout = 10000
logger.info(f"{self.__class__.__name__} is initializing...")
self._initialize(**kwargs)
logger.info(f"{self.__class__.__name__} has initialized")
def _initialize(self, **kwargs):
raise NotImplementedError()
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def visa_write(self, cmd: str):
"""
Send command to visa device
Equivalent to :py:func:`inst.write` in pyvisa class
"""
self.pyvisa_inst.write(cmd)
logger.info(f"{self.__class__.__name__} -> device: {cmd}")
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def visa_query(self, cmd: str):
"""
Send command to visa device and read output from device
Equivalent to :py:func:`inst.query` in pyvisa class
"""
logger.info(f"{self.__class__.__name__} -> device?: {cmd}")
res = self.pyvisa_inst.query(cmd)
logger.info(f"{self.__class__.__name__} <- device: {res}")
return res