Reactor Control System

A Python-based control system for laboratory reactors, supporting gas flow control, temperature management, and experimental automation.

Features

• Multi-device control: Brooks Mass Flow Controllers (MFC), HPLC pumps, Omega CN7600 temperature controllers, MKS ToolWEB pressure monitoring
• Three-layer architecture: Devices → Operations → Experiments for clean separation of concerns
• Experiment scripting: Pythonic Experiment API for running automated experiments
• Gas concentration control: MFC calibration with concentration-to-flow conversion
• Safety interlocks: HPLC temperature checks, built-in safety checks and step logging
• Data analysis: Steady-state analysis with conversion/selectivity calculations

Architecture

┌─────────────────────────────────────┐
│        Experiments Layer            │  src/experiments/
│  (High-level experiment scripts)    │
└────────────────┬────────────────────┘
                 │
┌────────────────▼────────────────────┐
│        Operations Layer             │  src/operations/
│  (Process control, safety checks)   │
└────────────────┬────────────────────┘
                 │
┌────────────────▼────────────────────┐
│         Devices Layer               │  src/devices/
│  (Hardware communication drivers)    │
└─────────────────────────────────────┘

Hardware

Device	Model	Protocol
Mass Flow Controller	Brooks 5850 series	RS-485 / Modbus
HPLC Pump	SSI	RS-232
Temperature Controller	Omega CN7600	RS-485 / Modbus
Pressure Monitor	MKS MG2000	ToolWEB / Ethernet

See docs/architecture_overview.md for full system design documentation.

Installation

# Create virtual environment
python -m venv .venv
source .venv/Scripts/activate  # Windows
# source .venv/bin/activate    # Linux/macOS

# Install dependencies
pip install -e .

Configuration

Device settings (COM ports, baud rates, addresses) are configured in src/core/config.py:

DEVICE_CONFIG = {
    "hplc": {"port": "COM3", "baud_rate": 9600},
    "mfc": {"port": "COM4", "baud_rate": 19200, "address": 0x02},
    "omega": {"port": "COM5", "baud_rate": 9600},
    "mks_toolweb": {"host": "192.168.100.100", "port": 2000},
}

MFC calibration data is stored in config/mfc_calibration.yaml.

Usage

Running an Experiment

from src.experiments import Experiment, Sample

exp = Experiment(name="steady-state", connect_devices=True)
exp.set_sample(Sample(
    batch_id="sample-001",
    mass_mg=50.0,
    operator="labuser",
    composition="Pd/Al2O3",
    metal="Pd",
    support="g-Al2O3",
    metal_loading_wt_percent=0.1,
    mesh_size="30-60",
    synthesis_method="incipient wetness",
))

# Pretreatment with multiple steps
exp = pretreatment(
    exp=exp,
    target_temps=[650, 400],
    ramp_rates=[10.0],
    hold_times=[240, 30],
    gas_flows=[
        {"total_flow_rate": None, "gas_concentrations": {"h2": 9300.0, "nh3": 0.0, "no": 0.0, "o2": 0.0, "h2o": 0.0}},
        {"total_flow_rate": 410, "gas_concentrations": {"h2": 9300.0, "nh3": 0.0, "no": 350.0, "o2": 0.0, "h2o": 20.0}},
    ],
)

# Steady-state experiment
exp = run_steady_state(
    exp=exp,
    target_temps=[120, 140, 160],
    ramp_rates=[10.0],
    hold_times=[30.0],
    gas_flow={
        "total_flow_rate": 410,
        "gas_concentrations": {"h2": 9300.0, "nh3": 0.0, "no": 350.0, "o2": 0.0, "h2o": 20.0},
    },
)

exp.standby()

Device Control (Low-level)

from src.devices.brooks_mfc import BrooksMFC

mfc = BrooksMFC(port="COM4", config=DeviceConfig())
mfc.connect()
mfc.set_flow_rate(50.0)  # SCCM
mfc.disconnect()

Project Structure

reactor_control/
├── src/
│   ├── analyze/       # Data analysis
│   ├── config/        # Configuration files
│   ├── core/          # Configuration, logging, utilities
│   ├── devices/       # Hardware drivers
│   ├── operations/    # Control operations
│   └── experiments/   # Experiment management
├── tests/             # Unit tests
├── docs/              # Documentation
└── hardware_manuals/  # Device specifications

Development

# Run tests
pytest tests/

# Lint code
ruff check src/

# Format code
ruff format src/

See docs/project_status.md for current development status.

Safety

Warning: This system controls physical instrumentation. Always verify hardware connections and safety interlocks before running experiments. Hardware tests should never be executed without explicit confirmation.