mfc

Python driver and command-line tool for MKS mass flow controllers.

Installation

pip install mfc

If you don't like pip, you can also install from source:

git clone https://github.com/numat/mfc.git
cd mfc
python setup.py install

Usage

This driver uses the ethernet port on the side of the device for communication. If you use this driver, you only need to provide power to the top ports.

###Command Line

To test your connection and stream real-time data, use the command-line interface. You can read the flow rate with:

$ mfc 192.168.1.200
{
  "actual": 4.99,
  "connected": true,
  "gas": "CO2",
  "ip": "192.168.1.200",
  "max": 37,
  "setpoint": 5.00,
  "temperature": 27.34
}

You can optionally specify a setpoint flow and gas with e.g. mfc 192.168.1.150 --set 7.5 --set-gas O2. See mfc --help for more.

###Python (Asynchronous)

Asynchronous programming allows us to send out all of our requests in parallel, and then handle responses as they trickle in. For more information, read through krondo's twisted introduction.

from mfc import FlowController
from tornado.ioloop import IOLoop, PeriodicCallback

def on_response(response):
    """This function gets run whenever a device responds."""
    print(response)

def loop():
    """This function will be called in an infinite loop by tornado."""
    flow_controller.get(on_response)

flow_controller = FlowController('192.168.1.200')

PeriodicCallback(loop, 500).start()
IOLoop.current().start()

This looks more complex, but the advantages are well worth it at scale. Essentially, sleeping is replaced by scheduling functions with tornado. This allows your code to do other things while waiting for responses.