---
id: pyvisa-sim
version: "0.7.1"
license: The MIT License Copyright (c) 2014 PyVISA-sim Authors and contributors. See AUTHORS Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated… (full text in the JSON record)
license_treatment: permissive
maintenance: active
---

# PyVISA-sim — Simulated backend for PyVISA implementing TCPIP, GPIB, RS232, and USB resources

License: permissive · Maintenance: active · Downloads: 188.1K/mo

## What it is and what it does

PyVISA-sim is a backend plugin for PyVISA that replaces the need for the National Instruments VISA library and physical instruments with a software simulation. It implements most methods for Message Based communication over GPIB, USB, Serial, and Ethernet in a simulated environment, allowing you to develop and test instrument control code on any machine without hardware. The behavior of simulated devices is controlled by a plain text configuration file, making it easy to model different instrument responses.

The package has been actively maintained since 2015, supports Python 3.10 through 3.13, and integrates seamlessly with PyVISA's dynamic backend loading system. It's particularly useful for CI/CD pipelines, offline development, and testing measurement scripts before deploying them to real hardware.

Use it for:

- Test PyVISA measurement scripts in CI/CD pipelines without physical instruments or NI-VISA installed
- Develop and debug GPIB/USB/Serial instrument control code offline on any machine
- Mock instrument responses for unit testing measurement acquisition routines
- Prototype new measurement workflows before deploying to real laboratory hardware
- Train or demonstrate instrument control without requiring expensive test equipment

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

PyVISA-sim provides a simulated VISA backend for PyVISA that lets you test instrument communication code without physical devices or the National Instruments VISA library installed.

Yes. PyVISA-sim fills a genuine gap for developers working with VISA-based instrument control: it eliminates the friction of installing NI-VISA and acquiring hardware just to test code. The package is actively maintained, has no known vulnerabilities, carries a permissive MIT license, and installs with minimal friction. Install it if you work with PyVISA and need to test offline or in automated environments.

## Install

pip install pyvisa-sim
uv add pyvisa-sim
poetry add pyvisa-sim

## Installing PyVISA-sim

Before you install: Low friction: pure Python wheel with four straightforward runtime dependencies (pyvisa, PyYAML, stringparser, typing-extensions). Actively maintained with recent commits and no known vulnerabilities.

License in practice: MIT license permits free use, modification, and distribution with minimal restrictions—suitable for both open-source and commercial projects.

Quickstart:

pip install pyvisa-sim

import pyvisa
rm = pyvisa.ResourceManager('@sim')
inst = rm.open_resource('GPIB0::1::INSTR')
response = inst.query('*IDN?')

Requires PyVISA 1.11+ and Python 3.10+; simulated device behavior must be configured via a plain text configuration file.

Verify before relying:

- Extent of VISA method coverage beyond 'most of the methods' for Message Based communication
- Whether simulated device behavior configuration supports all GPIB/USB/Serial/Ethernet protocol variants

## Package facts

- License: The MIT License Copyright (c) 2014 PyVISA-sim Authors and contributors. See AUTHORS Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated… (full text in the JSON record) (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 188.1K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

VISA simulator, mock instrument backend, GPIB USB serial simulation, PyVISA testing without hardware, instrument communication mock, VISA protocol simulator, measurement device emulation, instrument-simulation, testing-mock, hardware-abstraction

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