def plotdfmienc():

    cTCA = None

    chs=[]                                        ### Make list of lists to
    for i in range(13): chs+=[[]]                 ###   hold Clk & counters

    fyle = open('dfmienc_v2_110215_162959.tab')   ### Open the file
    fyle.readline()                               ### Skip 1 line (HEADER)

    for row in fyle.readlines():                  ### Loop over TABLE rows

      toks = row.split(',')                       ### Split row at commas

      if toks[0]<'"2011-02-15T04:37:42': continue ### Skip before TCA-90s
      if toks[0]>'"2011-02-15T04:40:42': continue ### Skip after TCA+90s

      for i,iCol in enumerate([2]+range(8,20)):   ### Loop Clock+count COLs
        val = max( 0.1 ,float(toks[iCol]) )       ### Extract COLUMN value,
        chs[i] += [val]                           ###  append to inner list

      if cTCA is None and \
      toks[0][1:20]=='2011-02-15T04:39:12':       ### At TCA, 
        cTCA = float(toks[2])                     ###   save DFMI Clock

    fyle.close()                                  ### Close the file

    ### At this point:

    ###   chs[0] is a list of the DFMI clock values;
    ###   chs[1] is a list of the A1a values;
    ###   chs[2] is a list of the A1b values;
    ###   ...
    ###   chs[5] is a list of the M1 values;
    ###   ...
    ###   chs[9] is a list of the m1 values;
    ###   ...

    import matplotlib.pyplot as plt               ### Import plot module

    plt.plot(chs[0],chs[5],'r',label='M1')        ### Plot DFMI clock vs M1
    plt.plot(chs[0],chs[9],'g',label='m1')        ### Plot DFMI clock vs m1
    plt.plot([cTCA,cTCA],[.1,max(chs[5]+chs[9])]
            ,'b',label='TCA')                     ### Plot vert line at TCA
    plt.semilogy()                                ### Plot on log Y scale
    plt.legend(loc='best')                        ### Draw legend
    plt.xlabel('DFMI Clock, s')                   ### Draw X label
    plt.ylabel('Threshold counter')               ### Draw Y label

    plt.show()                                    ### Show plot