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pyvisa / pyvisa-py

A pure python PyVISA backend
https://pyvisa-py.readthedocs.io
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Can't connect to usb instrument #3

Closed jonnojohnson closed 9 years ago

jonnojohnson commented 9 years ago

I'm on: Anaconda 2.1.0 (64 bit), Python 2.7.8 on Ubuntu 14.04 pyvisa 1.6.1.dev0 (updated today) pyvisa-py 0.1.dev0 pyusb 1.0.0b1

I have a Keysight scope connected over USB.

rm.list_resources() (u'USB0::10893::36894::Unknown::0::INSTR',)

scope = rm.open_resource('USB0::10893::36894::Unknown::0::INSTR') .... /home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/protocols/usbtmc.pyc in init(self, vendor, product, serial_number, device_filters, timeout, **kwargs) 160 except usb.core.USBError as e: 161 #self.log_error("Could not set configuration") --> 162 raise Exception('failed to set configuration') 163 164 self.usb_intf = self._find_interface(self.usb_dev, self.INTERFACE)

Exception: failed to set configuration

Any thoughts?

hgrecco commented 9 years ago

Yes. I have seen that in certain cases you need an extra:

self.usb_dev.set_configuration()

but not sure why. Is the original exception failing in line 158 or 159?

By the way, you can do: 

python -c "from pyvisa import util; util.get_debug_info()"

and you will get a nicely printed debug info. (Still needs to be improved but is a start)

jonnojohnson commented 9 years ago

What do you mean by the original exception?

Machine Details: Platform ID: Linux-3.13.0-37-generic-x86_64-with-debian-jessie-sid Processor: x86_64

Python: Implementation: CPython Executable: /home/mj-ubuntu/anaconda/bin/python Version: 2.7.8 Compiler: GCC 4.4.7 20120313 (Red Hat 4.4.7-1) Bits: 64bit Build: Aug 21 2014 18:22:21 (#default) Unicode: UCS4

PyVISA Version: 1.6.1.dev0

Backends: ni: Version: 1.6.1.dev0 (bundled with PyVISA) Binary library: Not found py: Version: 0.1.dev0 ASRL INSTR: Available TCPIP INSTR: Available USB INSTR: Available

jonnojohnson commented 9 years ago

Full traceback:

In [10]: scope = rm.open_resource('USB0::10893::36894::Unknown::0::INSTR')

Exception Traceback (most recent call last)

in () ----> 1 scope = rm.open_resource('USB0::10893::36894::Unknown::0::INSTR') /home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa/highlevel.pyc in open_resource(self, resource_name, access_mode, open_timeout, **kwargs) 1629 raise ValueError('%r is not a valid attribute for type %s' % (key, res.**class**.**name**)) 1630 -> 1631 res.open(access_mode, open_timeout) 1632 1633 for key, value in kwargs.items(): /home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa/resources/resource.pyc in open(self, access_mode, open_timeout) 157 logger.debug('%s - opening ...', self._resource_name, extra=self._logging_extra) 158 with self._resource_manager.ignore_warning(constants.VI_SUCCESS_DEV_NPRESENT): --> 159 self.session, status = self._resource_manager.open_bare_resource(self._resource_name, access_mode, open_timeout) 160 161 if status == constants.VI_SUCCESS_DEV_NPRESENT: /home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa/highlevel.pyc in open_bare_resource(self, resource_name, access_mode, open_timeout) 1593 :return: Unique logical identifier reference to a session. 1594 """ -> 1595 return self.visalib.open(self.session, resource_name, access_mode, open_timeout) 1596 1597 def open_resource(self, resource_name, /home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/highlevel.pyc in open(self, session, resource_name, access_mode, open_timeout) 177 cls = sessions.Session.get_session_class(parsed['interface_type'], parsed['resource_class']) 178 --> 179 sess = cls(session, resource_name, parsed) 180 181 return self._register(sess), constants.StatusCode.success /home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/sessions.pyc in **init**(self, resource_manager_session, resource_name, parsed) 154 constants.VI_ATTR_RSRC_CLASS: parsed['resource_class'], 155 constants.VI_ATTR_INTF_TYPE: parsed['interface_type']} --> 156 self.after_parsing() 157 158 def after_parsing(self): /home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/usb.pyc in after_parsing(self) 68 self.interface = usbtmc.USBTMC(int(self.parsed['manufacturer_id']), 69 int(self.parsed['model_code']), ---> 70 self.parsed['serial_number']) 71 72 for name in 'SEND_END_EN,TERMCHAR,TERMCHAR_EN'.split(','): /home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/protocols/usbtmc.pyc in **init**(self, vendor, product, serial_number, *_kwargs) 228 229 def **init**(self, vendor=None, product=None, serial_number=None, *_kwargs): --> 230 super(USBTMC, self).**init**(vendor, product, serial_number, **kwargs) 231 self.usb_intr_in = find_endpoint(self.usb_intf, usb.ENDPOINT_IN, usb.ENDPOINT_TYPE_INTERRUPT) 232 #self.log_debug('EP Address: intr={}'.format(self.usb_intr_in.bEndpointAddress)) /home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/protocols/usbtmc.pyc in **init**(self, vendor, product, serial_number, device_filters, timeout, **kwargs) 160 except usb.core.USBError as e: 161 #self.log_error("Could not set configuration") --> 162 raise Exception('failed to set configuration') 163 164 self.usb_intf = self._find_interface(self.usb_dev, self.INTERFACE) Exception: failed to set configuration
hgrecco commented 9 years ago

And can you try the following command:

import usb
print(usb.__version__)
print(usb.core.find()._ctx.backend.__class__.__module__.__name__.split('.')[-1])

(I am adding this to the debug info)

hgrecco commented 9 years ago

Sorry, the right command is:

usb.core.find()._ctx.backend.__class__.__module__.split('.')[-1]
hgrecco commented 9 years ago

or just update to the most recent (2 seconds ago) pyvisa-py and then:

python -c "from pyvisa import util; util.get_debug_info()"
hgrecco commented 9 years ago

I was looking at the PyUSB code and found that alt_setting should be optional. Can you try now?

jonnojohnson commented 9 years ago

Machine Details: Platform ID: Linux-3.13.0-37-generic-x86_64-with-debian-jessie-sid Processor: x86_64

Python: Implementation: CPython Executable: /home/mj-ubuntu/anaconda/bin/python Version: 2.7.8 Compiler: GCC 4.4.7 20120313 (Red Hat 4.4.7-1) Bits: 64bit Build: Aug 21 2014 18:22:21 (#default) Unicode: UCS4

PyVISA Version: 1.6.1.dev0

Backends: ni: Version: 1.6.1.dev0 (bundled with PyVISA) Binary library: Not found py: Version: 0.1.dev0 ASRL INSTR: Available via PySerial (N/A) TCPIP INSTR: Available USB INSTR: Available via PyUSB (1.0.0b1). Backend: libusb1

hgrecco commented 9 years ago

If install the current version from github (just pushed 10 min ago), does it still fails? With the same error?

jonnojohnson commented 9 years ago

Yes I just did: pip install -U https://github.com/hgrecco/pyvisa-py/zipball/master Then tried again & got the same failed to set configuration error.

hgrecco commented 9 years ago

Can you check /var/log/messages. Do you find something like usbfs: process NNNN (XYZ) did not claim interface 0 before use? If you do, it is likely a permission problem. This is something that was written some time ago by Florian Forster in the Lantz mailing list. 

Yes, you need the right udev rules to interact with the device. For
example, I created the file /etc/udev/rules.d/70-usbtmc.rules which
contains

# Agilent 34410A
SUBSYSTEM=="usb", ACTION=="add", ATTRS{idVendor}=="0957",
ATTRS{idProduct}=="0607", GROUP="plugdev", MODE="0660"

This grants read and write access to my Agilent 34410A (identified by
the vendor and product ids) for all users inside the "plugdev" group.

You can get the ids needed by the dmesg output or by lsusb (look for
ID:XXXX:YYYY where X=vendor and Y=product id).

For this, it is obviously crucial that your user is a member of plugdev
group (you can of course choose any group you see fit, for example
create a new group usbtmc; remember that you have to log out and log in
to refresh the group configurations).

If this is the case, we should find a way to achieve the same thing without manually putting each device into the rules. But it would be good to confirm that this is really the solution first.

hgrecco commented 9 years ago

Here is some more info: http://unix.stackexchange.com/questions/44308/understanding-udev-rules-and-permissions-in-libusb http://stackoverflow.com/questions/3738173/why-does-pyusb-libusb-require-root-sudo-permissions-on-linux

You might also try to run you python script using sudo, just for testing.

jonnojohnson commented 9 years ago

When I run IPython as sudo I now get this when trying to open the usb resource:

/home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/usb.pyc in after_parsing(self) 86 for name in 'SEND_END_EN,TERMCHAR,TERMCHAR_EN'.split(','): 87 attr = getattr(constants, 'VIATTR' + name) ---> 88 self.attrs[attr] = attr.default 89 90 def read(self, count):

AttributeError: 'int' object has no attribute 'default'

jonnojohnson commented 9 years ago

Repeated the attempt to open_resource (still as sudo) & got: /home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/protocols/usbtmc.pyc in init(self, vendor, product, serial_number, device_filters, timeout, **kwargs) 158 self.usb_dev.set_configuration() #self.CONFIGURATION 159 except usb.core.USBError as e: --> 160 raise Exception('failed to set configuration') 161 162 try:

Exception: failed to set configuration

hgrecco commented 9 years ago

I solved the AttributeError: 'int' object has no attribute 'default'

But still cannot reproduce failed to set configuration. I will check on a linux computer, because I suspect that this might be the problem.

hgrecco commented 9 years ago

For example, this is the output with an osci on my mac:

>>> import visa
>>> rm = visa.ResourceManager('@py')
>>> rm.list_resources()
('USB0::6833::1416::Unknown::0::INSTR',)
>>> inst = rm.open_resource('USB0::6833::1416::Unknown::0::INSTR')
>>> inst.query('*IDN?')
'Rigol Technologies,DS1052E,DS1ED122105695,00.02.04.00.01'

and using the ni backend:

>>> import visa
>>> rm = visa.ResourceManager()
>>> rm.list_resources()
('USB0::0x1AB1::0x0588::DS1K00005888::INSTR', 'ASRL1::INSTR', 'ASRL2::INSTR')
>>> inst = rm.open_resource('USB0::0x1AB1::0x0588::DS1K00005888::INSTR')
>>> inst.query('*IDN?')
'Rigol Technologies,DS1052E,DS1ED122105695,00.02.04.00.01'

Notice the only problem in this snippet with the py backend is that the resource name is malformed (this is due to a change in PyUSB) and that the serial ports are not listed.

hgrecco commented 9 years ago

And this are my debug info:

Machine Details:
   Platform ID:    Darwin-10.8.0-x86_64-i386-64bit
   Processor:      i386

Python:
   Implementation: CPython
   Executable:     /Users/grecco/envs/pyvisadev/bin/python3.4
   Version:        3.4.1
   Compiler:       GCC 4.2.1 (Apple Inc. build 5666) (dot 3)
   Bits:           64bit
   Build:          May 18 2014 00:54:21 (#v3.4.1:c0e311e010fc)
   Unicode:        UCS4

PyVISA Version: 1.6.1.dev0

Backends:
   ni:
      Version: 1.6.1.dev0 (bundled with PyVISA)
      #1: /Library/Frameworks/visa.framework/visa:
         found by: auto
         bitness: 32
   py:
      Version: unknown
      USB INSTR: Available via PyUSB (1.0.0b2). Backend: libusb0
      ASRL INSTR: Available via PySerial (10.8.0)
      TCPIP INSTR: Available
jonnojohnson commented 9 years ago

Ok I updated PyVISA-py just now and re-tried (using sudo) and now I can create the instrument:

In [4]: rm.list_resources()
Out[4]: 
(u'ASRL/dev/ttyS31::INSTR',
 u'ASRL/dev/ttyS30::INSTR',
 u'ASRL/dev/ttyS29::INSTR',
 u'ASRL/dev/ttyS28::INSTR',
 u'ASRL/dev/ttyS27::INSTR',
 u'ASRL/dev/ttyS26::INSTR',
 u'ASRL/dev/ttyS25::INSTR',
 u'ASRL/dev/ttyS24::INSTR',
 u'ASRL/dev/ttyS23::INSTR',
 u'ASRL/dev/ttyS22::INSTR',
 u'ASRL/dev/ttyS21::INSTR',
 u'ASRL/dev/ttyS20::INSTR',
 u'ASRL/dev/ttyS19::INSTR',
 u'ASRL/dev/ttyS18::INSTR',
 u'ASRL/dev/ttyS17::INSTR',
 u'ASRL/dev/ttyS16::INSTR',
 u'ASRL/dev/ttyS15::INSTR',
 u'ASRL/dev/ttyS14::INSTR',
 u'ASRL/dev/ttyS13::INSTR',
 u'ASRL/dev/ttyS12::INSTR',
 u'ASRL/dev/ttyS11::INSTR',
 u'ASRL/dev/ttyS10::INSTR',
 u'ASRL/dev/ttyS9::INSTR',
 u'ASRL/dev/ttyS8::INSTR',
 u'ASRL/dev/ttyS7::INSTR',
 u'ASRL/dev/ttyS6::INSTR',
 u'ASRL/dev/ttyS5::INSTR',
 u'ASRL/dev/ttyS4::INSTR',
 u'ASRL/dev/ttyS3::INSTR',
 u'ASRL/dev/ttyS2::INSTR',
 u'ASRL/dev/ttyS1::INSTR',
 u'ASRL/dev/ttyS0::INSTR',
 u'USB0::10893::36894::MY53240105::0::INSTR')

In [5]: scope = rm.open_resource('USB0::10893::36894::MY53240105::0::INSTR')

However I'm getting a timeout error when querying for idn.

In [6]: scope.query('*IDN?')
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-6-9571613806bc> in <module>()
----> 1 scope.query('*IDN?')

/home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa/resources/messagebased.pyc in query(self, message, delay)
    382         if delay > 0.0:
    383             time.sleep(delay)
--> 384         return self.read()
    385 
    386     # Kept for backwards compatibility.

/home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa/resources/messagebased.pyc in read(self, termination, encoding)
    307         if termination is None:
    308             termination = self._read_termination
--> 309             message = self.read_raw().decode(enco)
    310         else:
    311             with self.read_termination_context(termination):

/home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa/resources/messagebased.pyc in read_raw(self, size)
    281                     logger.debug('%s - reading %d bytes (last status %r)',
    282                                  self._resource_name, size, status)
--> 283                     chunk, status = self.visalib.read(self.session, size)
    284                     ret += chunk
    285             except errors.VisaIOError as e:

/home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/highlevel.pyc in read(self, session, count)
    289         # from the session handle, dispatch to the read method of the session object.
    290         try:
--> 291             return self.sessions[session].read(count)
    292         except KeyError:
    293             return constants.StatusCode.error_invalid_object

/home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/usb.pyc in read(self, count)
    100         term_char, _ = self.get_attribute(constants.VI_ATTR_TERMCHAR)
    101         while True:
--> 102             ret += self.interface.read(1)
    103             if ret[-1:] == term_char:
    104                 # TODO: What is the correct success code??

/home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/protocols/usbtmc.pyc in read(self, size)
    311             req = BulkInMessage.build_array(self._btag, recv_chunk, None)
    312 
--> 313             raw_write(req)
    314 
    315             resp = raw_read(recv_chunk)

/home/mj-ubuntu/anaconda/lib/python2.7/site-packages/pyvisa-py/protocols/usbtmc.pyc in write(self, data)
    202             return self.usb_send_ep.write(data)
    203         except usb.core.USBError as e:
--> 204             raise ValueError(str(e))
    205 
    206     def read(self, size):

ValueError: [Errno 110] Operation timed out

If I try to read the current timeout value I get a Runtime error:

RuntimeError: maximum recursion depth exceeded while calling a Python object

And if I try to set the timeout I also get and error:

Exception: Unknown attribute 1073676314
hgrecco commented 9 years ago

Timeout was not implemented for usb (I just did), but in any case this should not be the problem as the default is 2 seconds. I am surprised that is not working, I will install a linux and check. (The ASRL list looks horrible on linux, I am opening another issue for that)

hgrecco commented 9 years ago

I think this is solved. Feel free to reopen if necessary.

flutnic1 commented 9 years ago

hgrecco, I have the same timeout problem working with Keysight b2912a unit. Could you please tell me if you solved this problem ? If yes, how ?

Thanks in advance!

swirhun commented 8 years ago

I'm having a similar problem with an Agilent 34411A multimeter. The stack trace looks like this. Last week I was able to get about one '*IDN?' query out of the machine and then all subsequent writes and queries failed until I unplugged/replugged/reconnected. It seems there is some bug deep in USB protocol handler. The same code works for a Keithley 2110 multimeter, so it must be some small difference in how they interact over USB which is tripping up pyvisa-py.

Traceback (most recent call last): File "", line 1, in File "/usr/local/lib/python2.7/dist-packages/pyvisa/highlevel.py", line 1644, in open_resource res.open(access_mode, open_timeout) File "/usr/local/lib/python2.7/dist-packages/pyvisa/resources/resource.py", line 203, in open self.session, status = self._resource_manager.open_bare_resource(self._resource_name, access_mode, open_timeout) File "/usr/local/lib/python2.7/dist-packages/pyvisa/highlevel.py", line 1601, in open_bare_resource return self.visalib.open(self.session, resource_name, access_mode, open_timeout) File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/highlevel.py", line 191, in open sess = cls(session, resource_name, parsed) File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/sessions.py", line 184, in init self.after_parsing() File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/usb.py", line 176, in after_parsing self.parsed.serial_number) File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/protocols/usbtmc.py", line 232, in init super(USBTMC, self).init(vendor, product, serial_number, kwargs) File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/protocols/usbtmc.py", line 166, in init** raise Exception('failed to set configuration\n %s' % e) Exception: failed to set configuration [Errno 16] Resource busy

Here's an example where the first query succeeded but then it fails thereafter. Maybe there is a pyvisa-py problem in releasing the USB bus? Below, I query the DC range, I get 100mV as a response, but then I query it again and it fails due to a Pipe Error. Immediately prior, I set up i = rm.open_resource()

i.query('SENS:VOLT:DC:RANG?') u'+1.00000000E-01\n' i.query('SENS:VOLT:DC:RANG?') Traceback (most recent call last): File "", line 1, in File "/usr/local/lib/python2.7/dist-packages/pyvisa/resources/messagebased.py", line 407, in query return self.read() File "/usr/local/lib/python2.7/dist-packages/pyvisa/resources/messagebased.py", line 332, in read message = self.read_raw().decode(enco) File "/usr/local/lib/python2.7/dist-packages/pyvisa/resources/messagebased.py", line 306, in read_raw chunk, status = self.visalib.read(self.session, size) File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/highlevel.py", line 253, in read return self.sessions[session].read(count) File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/usb.py", line 102, in read usb.USBError) File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/sessions.py", line 313, in _read current = reader() File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/usb.py", line 96, in return self._read(lambda: self.interface.read(1), File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/protocols/usbtmc.py", line 307, in read raw_write(req) File "/usr/local/lib/python2.7/dist-packages/pyvisa-py/protocols/usbtmc.py", line 204, in write raise ValueError(str(e)) ValueError: [Errno 32] Pipe error

nat45928 commented 8 years ago

Did this ever get solved? I have a Keysight 34461A that is locking up frequently and needs to be disconnected and reconnected all the time.

swirhun commented 7 years ago

The problem we had with the Keithley 2230-3 has been resolved by sending a special (non-conforming) command upon connecting, to put the instrument in remote mode and clear its remote interface. It is unlike any other instrument I have used. I have also made small local customizations to pyvisa-py and pyusb to make them work with all our instruments now, so if anyone is looking for help I could publish some minor suggestions to GitHub. If I recall correctly, I bypassed the "language selection" portion and defaulted automatically to English, since it was causing problems with one Agilent instrument.

Paul

On Jul 7, 2017 01:04, "brandonrwin" notifications@github.com wrote:

@nat45928 https://github.com/nat45928 I had a similar problem with a 33500B. After locking up, the NI tools would report a protocol error for the next few reads and then eventually work, so perhaps it was partially equipment related. Updating the 33500B to the latest firmware fixed it for me.

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/pyvisa/pyvisa-py/issues/3#issuecomment-313542649, or mute the thread https://github.com/notifications/unsubscribe-auth/APcbhXNHHC1QzrFpAc2IIvFJFmp0KbqEks5sLWflgaJpZM4CyYiP .

swirhun commented 7 years ago

Hi nat45928,

Sorry, my last response was a bit off topic; I sent it by replying to an email on my phone :0. Have a look at https://github.com/pyvisa/pyvisa-py/issues/96. With some local customizations to pyvisa-py and pyusb, we are able to get reliable 34411A operation. I'm assuming the 34461A is a similar instrument. I can send you the changes I made if you want to diff them against your local copy of pyvisa-py and pyusb.

lilichen0 commented 3 years ago

I can not find the Keithley instrument 2230G-60-3 using Pyvisa in Linux. When I run rm.list_resources(), there only appear an ASRL, no USB device. The specific information is as follow:

lili@ubuntu:/$ python3 -c "from pyvisa import util; util.get_debug_info()" Machine Details: Platform ID: Linux-5.4.0-42-generic-x86_64-with-glibc2.29 Processor: x86_64

Python: Implementation: CPython Executable: /usr/bin/python3 Version: 3.8.5 Compiler: GCC 9.3.0 Bits: 64bit Build: Jul 28 2020 12:59:40 (#default) Unicode: UCS4

PyVISA Version: 1.11.3

Backends: ivi: Version: 1.11.3 (bundled with PyVISA)

1: /usr/lib/x86_64-linux-gnu/libvisa.so.0.0.0:

     found by: auto
     bitness: 64
     Could not get more info:
        VI_ERROR_NSUP_ATTR (-1073807331): The specified attribute is not defined or supported by the referenced object.

py: Version: 0.5.1 ASRL INSTR: Available via PySerial (3.5) USB INSTR: Available via PyUSB (1.1.0). Backend: libusb1 USB RAW: Available via PyUSB (1.1.0). Backend: libusb1 TCPIP INSTR: Available TCPIP SOCKET: Available GPIB INSTR: 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 funcionality. No module named 'gpib'

lili@ubuntu:/$ python3 Python 3.8.5 (default, Jul 28 2020, 12:59:40) [GCC 9.3.0] on linux Type "help", "copyright", "credits" or "license" for more information.

import pyvisa rm=pyvisa.ResourceManager('@py') rm.list_resources() ('ASRL/dev/ttyS0::INSTR',)