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pyvisa / pyvisa-py

A pure python PyVISA backend
https://pyvisa-py.readthedocs.io
MIT License
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pyvisa -py serial number cannot be read #210

Open yexub opened 4 years ago

yexub commented 4 years ago

I tried connect my device using GPIB-USB-HS, got "Found a device whose serial number cannot be read. The partial VISA resource name is: USB0::3034::5924::???::2::RAW ()" At 'sudo python' model, it will return '()'

And I tired to fix it by the method " https://techoverflow.net/2019/08/09/how-to-fix-pyvisa-found-a-device-whose-serial-number-cannot-be-read-the-partial-visa-resource-name-is-usb0-0instr/ " it will not find any USB instruments,and return ' ( ) '

python3 -m visa info Machine Details: Platform ID: Linux-4.18.0-80.7.1.el8_0.x86_64-x86_64-with-centos-8.0.1905-Core Processor: x86_64

Python: Implementation: CPython Executable: /usr/bin/python3 Version: 3.6.8 Compiler: GCC 8.2.1 20180905 (Red Hat 8.2.1-3) Bits: 64bit Build: Jul 1 2019 16:43:04 (#default) Unicode: UCS4

PyVISA Version: 1.10.1

Backends: ni: Version: 1.10.1 (bundled with PyVISA) Binary library: Not found py: Version: 0.3.1 ASRL INSTR: Available via PySerial (3.4) USB INSTR: Available via PyUSB (1.0.2). Backend: libusb1 USB RAW: Available via PyUSB (1.0.2). Backend: libusb1 TCPIP INSTR: Available TCPIP SOCKET: Available GPIB INSTR: Please install linux-gpib to use this resource type. No module named 'gpib'

MatthieuDartiailh commented 4 years ago

If you are using a USB to gpib adapter you should try to access your resource as GPIB not as USB. This means you will have to install linux-gpib. Also note that depending on the adapter linux gpib may not be able to list the resources but you should still be able to connect to it.

yexub commented 4 years ago

I have installed linux-gpib. I can get the resources list,

inst1.query('IDN?') 'KEITHLEY INSTRUMENTS INC.,MODEL 2400,685011?,C30 Mar 17 2006 09:29:29/A02 /F/E\n' inst1.read() '+9.910000E+37,+1.000029E-03,+9.910000E+37,+1.176638E+03,+3.789200E+04\n' inst.query('IDN?') 'KEITHLEY INSTRUMENTS INC.,MODEL 2182 ,0857394,A09 /A02 ' inst.read() Traceback (most recent call last): File "", line 1, in File "/usr/local/lib/python3.6/dist-packages/pyvisa/resources/messagebased.py", line 427, in read message = self._read_raw().decode(enco) File "/usr/local/lib/python3.6/dist-packages/pyvisa/resources/messagebased.py", line 400, in _read_raw chunk, status = self.visalib.read(self.session, size) File "/usr/local/lib/python3.6/dist-packages/pyvisa-py/highlevel.py", line 350, in read raise errors.VisaIOError(ret[1]) pyvisa.errors.VisaIOError: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

I use read method to read data, It works on 2400, but get errors on 2182,