pyvisa-sim

library0.7.1pypypi✓ verified 89d ago

PyVISA-sim is a Python library that provides a simulated backend for PyVISA, allowing users to develop and test instrument control applications without needing physical hardware. It supports common resource types like TCPIP, GPIB, RS232, and USB, mimicking their behavior. The current version is 0.7.1, released on 2024-05-13, and it follows a regular, active release cadence.

testing http-networking serialization

pip install pyvisa-sim

github ↗package ↗docs ↗changelog ↗

INSTALL

IMPORT

SIG · PYVISA-SIM

pyvisa-sim

testingpythonv0.7.1

Install

2.0s avg

Import

493ms

Disk

21MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.7.1 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.910 runs

installs and imports cleanly · install 0.0s · import 0.514s · 22.4MB

glibc

py 3.10–3.910 runs

installs and imports cleanly · install 2.0s · import 0.473s · 24MB

21MB installed

● package 21MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

ResourceManager

✓ import pyvisa; rm = pyvisa.ResourceManager('@sim')

Users typically interact with `pyvisa-sim` by specifying the `@sim` backend string to `pyvisa.ResourceManager`, rather than importing symbols directly from `pyvisa_sim`.

This quickstart demonstrates how to initialize PyVISA with the simulated backend, list available simulated resources, open a default simulated USB instrument, perform basic SCPI write and read operations, and properly close the instrument and resource manager.

import pyvisa # Create a resource manager that uses the simulated backend # The '@sim' string tells PyVISA to load pyvisa-sim as the backend rm = pyvisa.ResourceManager('@sim') # List available simulated resources (pyvisa-sim comes with some defaults) print("Available resources:", rm.list_resources()) # Open a simulated instrument resource # This instrument is defined within pyvisa-sim's default simulation try: instrument = rm.open_resource('USB::0x1000::0x2000::0x3000::INSTR') # Basic SCPI commands print("Writing '*IDN?'...") instrument.write('*IDN?') idn = instrument.read() print("Read IDN:", idn) # Example of a command that changes state (simulation only) instrument.write('MEASURE:VOLTAGE:DC?') voltage = instrument.read() print("Simulated DC Voltage:", voltage) # Close the instrument instrument.close() print("Instrument closed.") except Exception as e: print(f"An error occurred: {e}") finally: # Close the resource manager rm.close() print("Resource manager closed.")

Debug

Known issues

gotcha`pyvisa-sim` requires `pyvisa` to be installed and used. It's a backend plugin, not a standalone library. Trying to use it without `pyvisa` will lead to errors.

fix

Ensure `pyvisa` is installed: `pip install pyvisa`.

affects: All versions

gotchaTo engage the simulation, you MUST explicitly use the `@sim` backend string (e.g., `pyvisa.ResourceManager('@sim')`). If omitted or misspelled, PyVISA will attempt to connect to actual hardware or the default backend, leading to unexpected behavior or connection errors.

fix

Always initialize your resource manager with `rm = pyvisa.ResourceManager('@sim')`.

affects: All versions

gotcha`pyvisa-sim` provides *simulated* responses. While it aims to mimic real instruments, complex or highly specific instrument behaviors may not be perfectly replicated without further configuration (e.g., custom YAML files or programmatic resource registration).

fix

For specific instrument models or complex scenarios, consult the `pyvisa-sim` documentation on how to customize or extend the simulated instrument behavior.

affects: All versions

Errors

Common errors & fixes

pyvisa.errors.VisaIOError: VI_ERROR_RSRC_NFOUND (resource not found)

The specified resource string (e.g., 'USB::0x1000::0x2000::0x3000::INSTR') does not exist in the currently loaded simulation. `pyvisa-sim` provides default resources, but custom ones need to be configured.

fix

Check `rm.list_resources()` to see available resources. For custom resources, configure `pyvisa-sim` with a custom YAML file or by registering resources programmatically.

ValueError: No backend available for the given session. Make sure you have the 'pyvisa-sim' package installed and are using the '@sim' backend alias.

`pyvisa-sim` is not installed, or the `@sim` backend string is misspelled/missing when initializing `ResourceManager`.

fix

Install `pyvisa-sim` using `pip install pyvisa-sim`. Verify the backend string is exactly `'@sim'` when creating the resource manager.

AttributeError: module 'pyvisa_sim' has no attribute 'SomeClass'

Attempting to import or use a class directly from the `pyvisa_sim` module that is not intended for direct user interaction or does not exist.

fix

`pyvisa-sim` acts as a backend for `pyvisa`. Most user interaction should be via `pyvisa.ResourceManager('@sim')` and standard PyVISA methods, not by importing symbols directly from `pyvisa_sim`.

Upgrade

Version history

0.7.1latest on PyPI · released Sep 4, 2025

Audit

Dependencies

pyvisarequired`pyvisa-sim` acts as a backend for `pyvisa` and requires it for functionality.

Agent activity

7 hits · last 30 days

node

Amazon

Resources

githubhttps://github.com/pyvisa/pyvisa-sim ↗

packagehttps://pypi.org/project/pyvisa-sim/ ↗

docshttps://pyvisa-sim.readthedocs.io/en/latest/ ↗

changeloghttps://github.com/pyvisa/pyvisa-sim/blob/main/CHANGES.rst ↗