instro 1.20.0

Python library for talking to test instrumentation (power supplies, multimeters, electronic loads, DAQs, oscilloscopes, PLCs) from a unified, typed API.

Quickstart

Talk to a simulated PSU. No hardware required.

# Terminal 1: start the in-process SCPI sim server:
python -m instro.psu.scpi_sim_server

# Terminal 2: run this:
from instro.psu import InstroPSU
from instro.psu.drivers import SimulatedPSU

with InstroPSU(
    name="my-psu",
    driver=SimulatedPSU("TCPIP0::127.0.0.1::5025::SOCKET"),
    num_channels=2,
) as psu:
    psu.set_voltage(3.3, channel=1)
    psu.output_enable(True, channel=1)
    print(psu.get_voltage(channel=1))

That's the flow. Construct, open(), configure, measure, close(). When you want to capture the data, attach a publisher to stream it to a file, a custom destination, or Nominal. For the full walkthrough (including the background polling daemon and publishers), see the official documentation.

Installation

pip install instro

Requires Python 3.10 to 3.14.

To work on instro itself, clone and install with uv:

git clone https://github.com/nominal-io/instro.git
cd instro
uv sync

This creates a virtual environment with the core library and the default development/test dependencies, including the EtherNet/IP, contrib, and unstable workspace packages. Add vendor extras as needed, for example uv sync --extra nidaq; uv sync --extra all selects all defined extras but does not install proprietary system SDKs. Run with uv run python your_script.py or activate via source .venv/bin/activate (Unix) / .venv\Scripts\activate (Windows).

The default development environment builds the local EtherNet/IP extension and needs Rust and a C/C++ compiler/linker. Full workspace checks also need CMake, LLVM/libclang, and a separate nightly rustfmt installation. See Prerequisites in the contributing guide before syncing a fresh checkout.

Optional Extras

Instro drivers that require a separate vendor sdk installation ship as separate packages so the heavy dependencies stay optional, and community-contributed drivers ship in their own package. Install only what you need:

Extra	Pulls in	Package
instro[nidaq]	NI-DAQmx (Linux + Windows)
instro[labjack]	LabJack LJM
instro[mccdaq]	MCC UL (Windows-only)
instro[aardvark]	Total Phase Aardvark (I2C)
instro[ethernetip]	EtherNet/IP support for Allen-Bradley PLCs
instro[contrib]	Community-contributed hardware drivers
instro[unstable]	In-development features whose API isn't settled
instro[all]	Everything above	—

Pass the extra package name in brackets to pip install:

pip install "instro[labjack]"
pip install "instro[nidaq,contrib]"

Supported devices

Don't see your vendor? Drivers we can't test directly land in instro-contrib. Install them with instro[contrib]. See CONTRIBUTING.md for the verification expectations.

Contributing

• Humans: see CONTRIBUTING.md for development setup, PR conventions, and where different kinds of contributions belong in the workspace.
• AI coding tools (Claude Code, Cursor, Codex, Copilot Workspace, …): see AGENTS.md for codebase landmarks, conventions, and common workflows. The repo ships reusable skills and subagents for both Claude Code (.claude/) and Codex CLI (.agents/, .codex/). The existing skills are add-instrument-driver which scaffolds a new vendor driver from a programming manual/API, and validate-driver-hardware which smoke-tests an authored driver against the real instrument and self-corrects it. See Repo skills and subagents.

License

Apache License 2.0. Third-party dependency notices and proprietary vendor runtime requirements are documented in NOTICE.