severstar-mfc-rs485 0.1.0

Python code for RS485 communication with Severstar MFC

Severstar MFC RS485 Control

A comprehensive Python package for RS485 communication with Severstar CS series digital mass flow controllers (MFCs) from Beijing Sevenstar Flow Co., Ltd.

Features

• Full Protocol Support: Complete implementation of CS系列MFC通讯协议V2.3
• High-level API: Easy-to-use interface for common MFC operations
• CLI Tool: Command-line interface for device management and monitoring
• Comprehensive Error Handling: Robust exception hierarchy for reliable operation
• Type Annotations: Full type support for better development experience
• Cross-platform: Works on Windows, Linux, and macOS

Supported Devices

• CS100 series digital mass flow controllers
• CS200 series digital mass flow controllers
• Other CS series devices with RS485 interface

Installation

pip install severstar-mfc-rs485

Quick Start

Python API

from severstar_mfc_rs485 import SeverstarMFC, discover_mfc_devices

# Discover devices
devices = discover_mfc_devices('/dev/ttyUSB0')
print(f"Discovered devices: {devices}")

# Connect to device
with SeverstarMFC('/dev/ttyUSB0', address=32) as mfc:
    # Get device information
    info = mfc.get_device_info()
    print(f"Serial: {info['serial_number']}")
    
    # Monitor flow rate
    flow_rate = mfc.get_flow_rate()
    print(f"Current flow: {flow_rate:.4f} FS")
    
    # Set flow to 50%
    mfc.set_flow_rate(0.5)

Command Line Interface

# Discover devices
severstar_mfc_rs485 discover /dev/ttyUSB0

# Get device info
severstar_mfc_rs485 info /dev/ttyUSB0 --address 32

# Monitor status
severstar_mfc_rs485 status /dev/ttyUSB0 --address 32

# Set flow rate
severstar_mfc_rs485 set-flow /dev/ttyUSB0 0.5 --address 32

Documentation

• Usage Guide: Comprehensive usage examples and API reference
• Protocol Reference: Detailed protocol specification
• Installation Guide: Setup and installation instructions

Protocol Support

The package implements the complete CS series MFC communication protocol including:

• Control Mode: Closed loop, open loop, manual valve control
• Flow Control: Setpoint reading/writing, flow rate monitoring
• Valve Control: Valve output reading/writing
• Calibration: Full scale flow, zero flow, gas conversion factors
• Temperature Monitoring: Sensor and environment temperature
• Totalizer: Accumulated flow and operating time
• Alarms: Status and configuration
• Device Identification: Serial number, model, firmware version
• Communication Settings: MAC address, baud rate configuration

API Overview

Main Classes

• SeverstarMFC: High-level device interface
• MFCCommunicator: Low-level RS485 communication
• MFCCommands: Command-level operations
• ProtocolMessage: Protocol message encoding/decoding

Data Types

• ServiceType: Read/Write service types
• CommandClass: Protocol command classes
• ControlMode: Control mode enumerations
• DataFormat: Data conversion utilities

Examples

Basic Monitoring

import time
from severstar_mfc_rs485 import SeverstarMFC

def monitor_device(port, address):
    with SeverstarMFC(port, address) as mfc:
        while True:
            status = mfc.get_status()
            print(f"Flow: {status['flow_rate']:.4f} FS | "
                  f"Temp: {status['sensor_temperature']:.1f}°C")
            time.sleep(1)

monitor_device('/dev/ttyUSB0', 32)

Flow Profile Control

from severstar_mfc_rs485 import SeverstarMFC
import time

profile = [
    (0.0, 2.0),   # 0% for 2s
    (0.5, 5.0),   # 50% for 5s
    (0.8, 3.0),   # 80% for 3s
    (0.0, 1.0)    # 0% for 1s
]

with SeverstarMFC('/dev/ttyUSB0', 32) as mfc:
    for flow, duration in profile:
        mfc.set_flow_rate(flow)
        time.sleep(duration)

Error Handling

from severstar_mfc_rs485 import (
    CommunicationError, TimeoutError, InvalidParameterError
)

try:
    with SeverstarMFC('/dev/ttyUSB0', 32) as mfc:
        mfc.set_flow_rate(2.0)  # Invalid value
except InvalidParameterError as e:
    print(f"Invalid parameter: {e}")
except CommunicationError as e:
    print(f"Communication error: {e}")

Development

Installation from Source

git clone https://github.com/gavinlouuu-kpt/severstar_mfc_rs485.git
cd severstar-mfc-rs485
pip install -e .

Running Tests

python -m pytest tests/ -v

License

This project is licensed under the MIT License - see the LICENSE file for details.

Support

For issues and questions, please open an issue on the GitHub repository.

Acknowledgments

• Beijing Sevenstar Flow Co., Ltd. for the CS series MFC devices and protocol documentation
• PySerial team for excellent serial communication library
• Typer team for the wonderful CLI framework

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This package is not affiliated with or endorsed by Beijing Sevenstar Flow Co., Ltd.