instro 0.14.0

Typed Python API for test-and-measurement instruments: power supplies, multimeters, electronic loads, DAQs, and more

⟢ instro

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

Installation

pip install instro

Requires Python 3.10 to 3.13.

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

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

This creates a virtual environment with the core library, all optional vendor drivers, and dev dependencies. Run with uv run python your_script.py or activate via source .venv/bin/activate (Unix) / .venv\Scripts\activate (Windows).

For the full toolchain needed to run just check and just test (including the native Rust/CMake/LLVM dependencies that just test requires), see Prerequisites in the contributing guide.

Optional extras

Native-SDK drivers ship as separate workspace packages so the heavy dependencies stay optional, and community-contributed drivers ship in their own package. Install only what you need:

Extra	Pulls in
instro[nidaq]	NI-DAQmx (Linux + Windows)
instro[labjack]	LabJack LJM
instro[mccdaq]	MCC UL (Windows-only)
instro[daq]	All three DAQ vendor SDKs
instro[aardvark]	Total Phase Aardvark (I2C); alias: instro[i2c]
instro[ethernetip]	EtherNet/IP support for Allen-Bradley PLCs (native backend)
instro[contrib]	Community-contributed drivers for devices the maintainers can't verify directly
instro[all]	Everything above

Quickstart

Talk to a simulated PSU. No hardware required.

# Terminal 1: start the in-process SCPI sim server:
uv run 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.output_enable(True, channel=1)
    psu.set_voltage(3.3, channel=1)
    print(psu.get_voltage(channel=1))  # Measurement(channel_data={'my-psu.ch1.voltage': [3.31...]}, ...)

That's the whole loop: 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.

Supported devices

Category	Class	Vendors
Power supply	InstroPSU	B&K Precision (9115, 914X), Keysight (E36100-series), Rigol (DP800-series), Siglent (SPD3303), TDK Lambda (Genesys), simulated
Multimeter	InstroDMM	Agilent 34401A, Keithley 2400
Electronic load	InstroELoad	B&K Precision (85xxB-series)
Oscilloscope	InstroScope	Keysight (1200X-series), Tektronix (2-series), Siglent (SDS1000X-E)
DAQ	InstroDAQ	Keysight 34980A, NI-DAQmx, LabJack T-series, MCC USB-series
I2C	I2CInterface	Total Phase Aardvark
Modbus	ModbusDevice	Any Modbus TCP / RTU device
EtherNet/IP	EtherNetIPDevice	Allen-Bradley / CompactLogix-class PLCs

Don't see your vendor? Drivers the maintainers can't verify directly against the device land in instro-contrib on contributor verification — install them with instro[contrib]. See CONTRIBUTING.md for the bar.

Documentation

Full guides, API reference, and per-category walkthroughs live at instro.nominal.io.

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.