Python access to Gamma vacuum QPC ion pump pressure gauge using Ethernet interface

gammaqpc.py

import socket

def fetchGammaPressure(host, pumpindex):
	s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
	s.settimeout(2)

	try:
		s.connect((host, 23))
	except:
		print('Failed to connect to Gamma QPC')
		return False

	# First fetch prompt
	while True:
		chunk = s.recv(1)
		if chunk == b'':
			print('Failed to receive')
			s.close()
			return False
		if chunk.decode("utf-8") == ">":
			break

	# Received prompt, transmit our command
	s.send(('spc 0B '+str(pumpindex)+"\r\n").encode())

	# Wait for reply and read till end of line marker
	repl = ''
	while True:
		chunk = s.recv(1)
		if chunk == b'':
			print('Failed to receive')
			s.close()
			return False
		if chunk.decode("utf-8") == ">":
			break
		repl = repl + chunk.decode("utf-8")

	s.close()

	# Parse

	repl = repl.split(" ")

	if(len(repl) < 4):
		print("Failed to read response from GammaQPC")
		return False

	if(repl[0] != "OK"):
		print("Failed to read response from GammaQPC")
		return False

	if(repl[3] != 'MBAR\r\r\n'):
		print("Gamma QPC not set to MBAR")
		return False

	pressure = float(repl[2])
	return pressure

if __name__ == "__main__":
  import sys

  if(len(sys.argv) < 3):
    print("Usage: "+sys.argv[0]+" HOSTNAME PORT")
  else:
    try:
      host = sys.argv[1]
      index = int(sys.argv[2])

      if((index < 1) or (index > 4)):
        print("Invalid index, for QPC index has to be in range 1 to 4 inclusive")
        sys.exit()

      pressure = fetchGammaPressure(host, index)

      if(pressure == 1.3e-11):
        print("Result is 1.3e-11 mbar, this is also signalled if the QPC has no pump attached ...")
        sys.exit()

      print(str(pressure)+" mbar")
    except:
      print("Failed to query host "+host+" for pump "+str(index))

LICENSE.md

Copyright (c)2021 Thomas Spielauer. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

sample.py

import gammaqpc

import sys

if(len(sys.argv) < 3):
  print("Usage: "+sys.argv[0]+" HOSTNAME PORT")
  sys.exit()

try:
  host = sys.argv[1]
  index = int(sys.argv[2])

  if((index < 1) or (index > 4)):
    print("Invalid index, for QPC index has to be in range 1 to 4 inclusive")
    sys.exit()

  pressure = gammaqpc.fetchGammaPressure(host, index)

  if(pressure == 1.3e-11):
    print("Result is 1.3e-11 mbar, this is also signalled if the QPC has no pump attached ...")
    sys.exit()

  print(str(pressure)+" mbar")
except:
  print("Failed to query host "+host+" for pump "+str(index))