1 #! /usr/bin/env python
   2 #
   3 # getgpibdata.py
   4 #
   5 # This script will get data from an Agilent 4395A network analyzer
   6 # and spits out the data into standard output.
   7 # The output format is a space delimited list, each row representing a frequency point.
   8 # The meanings of columns are:
   9 #<Network analyzer mode>
  10 # freq  real  imag  
  11 #<Spectrum analyzer mode>
  12 # freq  mag1  [mag2]
  13 # mag2 is present only when the dual channel mode is active. 
  14 #
  15 # Yoichi Aso  Aug 26 2008
  16 
  17 import re
  18 import Gpib
  19 device = Gpib.Gpib("ag4395a")  
  20 
  21 #Put the analyzer on hold
  22 device.write("HOLD")    
  23 
  24 #Get the number of data points
  25 device.write("POIN?")    
  26 numPoints = device.read(30)
  27 numPoints = int(numPoints)
  28 
  29 #Set the output format to ASCII
  30 device.write("FORM4")
  31 
  32 #Get the frequency points
  33 device.write("OUTPSWPRM?")    
  34 freq = device.read(23*numPoints)
  35 
  36 #Break the data into lists
  37 freqList = re.findall(r'[-+.E0-9]+',freq)
  38 
  39 #Check for the analyzer mode
  40 device.write("NA?") 
  41 analyzerMode = int(device.read())
  42 
  43 if analyzerMode == 1:
  44     # It is the network analyzer mode    
  45     # In this mode, the data format is real,imag for each frequency point
  46     #Get the data
  47     device.write("OUTPDATA?")
  48     data=device.read(15*numPoints*2);
  49 
  50     #Break the data into lists
  51     dataList = re.findall(r'[-+.E0-9]+',data)
  52 
  53     # Print data
  54     j=0;
  55     for i in range(len(freqList)):
  56         print freqList[i], dataList[j], dataList[j+1]
  57         j=j+2;
  58 
  59 else:
  60     # It is spectrum analyzer mode
  61 
  62     #Check if it is the dual channel mode or not
  63     device.write('DUAC?')
  64     numOfChan = int(device.read()) +1
  65 
  66     #Get the data
  67     dataList=[]
  68     for i in range(1,numOfChan+1):
  69         device.write("OUTPDATA?")
  70         data=device.read(15*numPoints)
  71         #Break into elements
  72         data=re.findall(r'[-+.E0-9]+',data)
  73         #Append to dataList
  74         dataList.append(data)
  75 
  76     # Print data
  77     for i in range(len(freqList)):
  78         print freqList[i],
  79         for j in range(0, numOfChan):
  80             print dataList[j][i],
  81         
  82         print
  83 
  84 
  85 
  86 #Resume the measurement
  87 device.write("CONT")