nbs-sim

nbs-sim provides a configurable EPICS simulation IOC for NBS beamline environments. It builds a caproto-based IOC from startup configuration files and simulated device classes so UIs and orchestration systems can be exercised without hardware.

Features

• Loads simulated devices from configuration
• Exposes PVs through a caproto IOC.
• Supports startup from a profile startup directory or explicit config file paths.
• Includes simulation device classes for motors, shutters, detectors, optics, and beamline-specific components.

Requirements

• Python >=3.8
• Runtime dependencies from pyproject.toml:
  • caproto
  • scipy
  • numpy
  • nbs-bl
  • nbs-core

Installation

pip (editable)

pip install -e .

pixi

If you use pixi in this monorepo:

pixi install
pixi run python -m pip install -e .

Running the IOC

The CLI entrypoint is nbs-sim.

Option 1: startup directory

Point to a startup directory that contains:

• devices.toml
• sim_conf.toml

nbs-sim --startup-dir /path/to/startup --list-pvs

Option 2: explicit file paths

nbs-sim \
  --device-file /path/to/devices.toml \
  --config-file /path/to/sim_conf.toml \
  --list-pvs

If neither --startup-dir nor both config file options are provided, startup exits with a CLI error.

How it works

• nbs_sim.beamline:main parses CLI arguments and loads device configuration.
• generate_device_config merges the device and simulation configuration files.
• loadFromConfig instantiates devices with createIOCDevice.
• The IOC is started with caproto run(...).

Development

Install development tools:

pip install -e ".[dev]"

Run tests:

pytest

Format and lint:

black src
flake8 src

Package layout

• src/nbs_sim/beamline.py: CLI entrypoint and IOC assembly.
• src/nbs_sim/load.py: device factory helper used by autoload.
• src/nbs_sim/devices/: simulation device implementations.

Notes

• Project status is currently alpha.
• This package expects configuration files generated or maintained by the broader NBS beamline stack.