nanodac Module

A MADSci node module for the Eurotherm nanodac temperature/process controller, communicating over Modbus/TCP. Deployed at APS beamline 9-BM.

Layers

• src/nanodac_interface.py — Nanodac driver class: connect / disconnect, get_status, and get_temperature / set_temperature (plus setpoint, working setpoint, output, mode). Pure Modbus/TCP via pymodbus, no MADSci dependency.
• src/nanodac_rest_node.py — NanodacNode(RestNode): wraps the driver as a MADSci REST node with actions get_temperature, get_setpoint, set_temperature, get_output.

This is a simple device — no MADSci resource tracking is used.

nanodac Modbus specifics

Confirmed on nanodac v5.50 (slave id 1):

• Loop.1.Main parameters start at base address 512 (Loop.2 at 640, +128 apart) — not the canonical register 1.
• REAL (float) parameters are read/written through the IEEE-float mirror: int_address + 0x8000, two 16-bit registers, big-endian high-word-first.
• Unwritten floats read back as the sentinel (0x0000, 0x8000) (~4.59e-41), mapped to None.
• Bool/enum params (AutoMan, etc.) are plain 1-register int reads.

Install

git clone https://github.com/AD-SDL/nanodac_module.git
cd nanodac_module
pdm install            # dev on the private subnet: prefix with the SOCKS proxy env (see below)

Or, using released packages directly:

pip install -e .

Configure

Edit node.settings.yaml (discovered via MADSci walk-up), or override via env vars / CLI:

Setting	Default	Description
nanodac_ip	(required)	Controller IP (Modbus/TCP)
nanodac_port	502	Modbus/TCP port
unit_id	1	Modbus slave/unit id
loop	1	Default control loop
node_url	—	REST API base URL (e.g. http://0.0.0.0:2010)

Run

# quick driver smoke test (no MADSci needed)
python src/nanodac_interface.py

# run the REST node
python -m nanodac_rest_node          # or: pdm run python -m nanodac_rest_node

Or via Docker (base image ghcr.io/ad-sdl/madsci:latest):

docker compose up

compose.yaml mounts node.settings.yaml and .madsci/ into the container and runs python -m nanodac_rest_node.

Development

ruff check src/        # lint
ruff format src/       # format
pre-commit install     # enable the pre-commit hooks

docs/Configuration.md and .env.example are auto-generated by pydantic-settings-export (wired into pyproject.toml and the pre-commit config) from NanodacNodeConfig; do not edit them by hand.

Private-subnet install note

If the controller host has no direct internet (private subnet), install packages through your lab's SOCKS proxy:

export ALL_PROXY=socks5h://<proxy-host>:<port>
export HTTPS_PROXY=$ALL_PROXY HTTP_PROXY=$ALL_PROXY https_proxy=$ALL_PROXY http_proxy=$ALL_PROXY

Status

Read actions (get_temperature, get_setpoint, get_output, state polling) are validated against nanodac v5.50. set_temperature is experimental/unverified — the setpoint-write path on this firmware still needs confirmation via the Eurotherm comms manual (HA030554) / iTools; see the note in set_temperature.