#!/usr/bin/env python
  """
  Created on Mon Aug 19 15:52:23 2013
  53230a_freq_acq.py
  This program is made to communicate with the counter
  Agilent 53230A.
  @author: Serge Grop
  """
  
  import sys
  import argparse
  import socket
  import time
  import os
  
  DEVICE_IP = '192.168.0.74'
  DEVICE_PORT = 5025 # Agilent have standardized on using port 5025 for SCPI
  #socket services.
  GATE_TIME = 1 # Gate time for one measurement
  OFILENAME = '' #File header
  IN_COUP = 'AC' # Input coupling
  IN_IMP = '50' # Input impedance
  IN_CH = '1' # Input channel
  
  #==============================================================================
  def parse():
      """ Specific parsing procedure for transfering data from 53230a
      counter.
      Return parsed arguments."""
      parser = argparse.ArgumentParser( \
          description='Acquire data from 53230a counter connected '\
          'through Ethernet.',
          epilog='Example: \'53230a_acq_freq -o toto -c DC -i 1M \' configure ' \
          '53230a_acq_freq with output file toto-"date".dat, input coupling DC '\
          'and input impedance 1 MOhms.')
      parser.add_argument('-o', action='store', dest='ofile', \
                          default=OFILENAME,\
                          help='Output data filename (default '+OFILENAME+')')
      parser.add_argument('-c', action='store', dest='input_coupling', \
                          default=IN_COUP,\
                          help='Input coupling AC or DC (default '+IN_COUP+')')
      parser.add_argument('-i', action='store', dest='input_impedance', \
                          default=IN_IMP,\
                          help='Input impedance 50 or 1M (default '+IN_IMP+')')
      parser.add_argument('-t', action='store', dest='gatetime', \
                          default=GATE_TIME,\
                          help='Gate time for one measurement'\
                          ' (default '+str(GATE_TIME)+' second)')
      parser.add_argument('-ip', action='store', dest='ip', \
                          default=DEVICE_IP, help='IP address of the counter'\
                          ' (default '+str(DEVICE_IP)+')')
      parser.add_argument('-p', action='store', dest='port', \
                          default=DEVICE_PORT, help='Port of the counter'\
                          ' (default '+str(DEVICE_PORT)+')')
      parser.add_argument('-ch', action='store', dest='input_channel', \
                          default=IN_CH,\
                          help='Input channel (default '+IN_CH+')')
      args = parser.parse_args()
      return args
  
  #==============================================================================
  def connect(ip,port):
      """Creation of a socket to establish the communication
      with 53230a counter"""
      try:
          print '53230a connection state at "%s" ?' % ip
          sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM, \
          socket.IPPROTO_TCP)
          sock.settimeout(5) 		# Don't hang around forever
          sock.connect((ip, port)) # Start the connection
          print '  --> Connected'
          return sock
      except socket.error as ex: # Debugging
          if 'Connection refused' in ex:
              print 'Wrong PORT (Default PORT : 5025)
  ', ex
              print '
    --> Not connected'
          elif 'No route to host' in ex:
              print 'Wrong address (Default address : 169.254.2.30)
  ', ex
              print '
    --> Not connected'
          else:
              print ex+'
  '+'  --> Not connected'
          sys.exit()
  
  #==============================================================================
  def init_53230a(sock, coupling, impedance, gatetime, channel):
      """Initialization of the counter"""
      g_time = 'SENS:FREQ:GATE:TIME '+str(gatetime)+'
  ' # Definition of
      #the string to initialize the gate time
      sock.send("*RST
  ") #Main reset
      sock.send("DISP:DIG:MASK:AUTO OFF
  ") # Disable display autodigits
      if impedance == '50':
          sock.send("INP"+channel+":IMP 50
  ") # Input 1 impedance : 50 Ohms
      else:
          sock.send("INP"+channel+":IMP 1.0E6
  ") # Input 1 impedance : 1 MOhms
      if coupling == 'AC':
          sock.send("INP"+channel+":COUP AC
  ") # Input 1 coupling mode AC
      else:
          sock.send("INP"+channel+":COUP DC
  ") # Input 1 coupling mode DC
      sock.send("SYST:TIM INF
  ") # Timeout infiny to avoid problem if the gate
      #is too long
      sock.send("CONF:FREQ (@"+channel+")
  ") # Signal on input 1
      sock.send("SAMP:COUN 1E6
  ") # Number of samples : 1 million (max)
      # the number of samples in continous mode is limited
      # by the size of the memory
      sock.send("SENS:FREQ:MODE CONT
  ") # Continuous mode (gap free) enable
      sock.send("SENS:FREQ:GATE:SOUR TIME
  ") # The gate source is TIME
      sock.send(g_time) # Gate time : 1 second
      sock.send("TRIG:SOUR IMM
  ") # Because of the continuous mode
  
  #==============================================================================
  def check_error(sock):
      """Used for debugging during the development of the program,
      not used anymore"""
      sock.send('SYST:ERR?
  ')
      error = None
      try:
          error = sock.recv(128)
      except socket.timeout:
          error = ""
      print error
  
  #==============================================================================
  def read_buffer(sock):
      """Read the data returned by the counter 53230a until the '
  '"""
      ans = ''
      nb_data_list = []
      nb_data = ''
      while ans != '
  ':
          ans = sock.recv(1)
          nb_data_list.append(ans) # Return the number of data
      list_size = len(nb_data_list)
      for j in range (0, list_size):
          nb_data = nb_data+nb_data_list[j]
      return(nb_data) # Return the number of data in the memory
  
  
  #==============================================================================
  def acqu_53230a(i, sock, data_file, gatetime):
      """Frequency acquisition and stockage in a file"""
      sock.send("INIT:IMM
  ") # Start the acquisition immediatly
      print "Waiting for the first acquisition"
      while True:
          try:
              sock.send("DATA:POIN?
  ") # Ask the number of data in the memory
              nb_data = read_buffer(sock) # Number of data available (string)
              #nb_data_int = int(nb_data) # Convert in integer
              #epoch time
              epoch = time.time()
              #MJD time
              mjd = epoch / 86400.0 + 40587
              if nb_data != '+0
  ': # There is a minimum of one data to read
                  try:
                      sock.send("DATA:REM? 1
  ") # Put the data in the buffer and
                      # clear the memory
                      freq = sock.recv(24) # Read the buffer
                      freq = freq[:22] # Remove 
   from the string
                      freq = freq.replace("+", "")
                      freq = freq.replace("E", "e")
                      freq = freq.replace("\t", "")
                      sample = "%f\t%f\t%s
  " % (epoch, mjd, freq)
                      data_file.write(sample) # Write in a file
                      print sample
                  except Exception as ex:
                      print "Exception during counter data reading: " + str(ex)
              else:
                  #print "Waiting for the next acquisition"
                  #pass
                  time.sleep(int(gatetime)*0.1) # Wait the time of the gate time
                  #to avoid too much check of the memory
          except KeyboardInterrupt:
              break # To stop the loop in a clean way
  
  #==============================================================================
  def main():
      """Main program"""
      args = parse() # Parse command line
      ofile = args.ofile # Data output file
      ip = args.ip
      coup = args.input_coupling
      imp = args.input_impedance
      gate_time = args.gatetime
      port = args.port
      ch = args.input_channel
      i = 0 #Init the number of sample
      sock = connect(ip, port)
      filename = time.strftime("%Y%m%d-%H%M%S", \
      time.gmtime(time.time()))+'-AG53230A_cont.dat' # Define the name of the file :
      # "experiment"+"date and hour".dat
      data_file = open(filename, 'wr', 0) # Create the file in write and read
      # mode, the file is updated at each sample
      #data_file.write('#Number of the sample-frequency in Hz-'\
      #'date when the data is computed
  ')
      init_53230a(sock, coup, imp, gate_time, ch)
      acqu_53230a(i, sock, data_file, gate_time)
      sock.close()
      print '
    --> Disconnected'
      data_file.close()
      try:
          ans = raw_input('Would you like to keep this datafile'\
          '(y/n : default y)?\t')
          if ans == 'n':
              os.remove(filename)
              print '
  ', filename, 'removed
  '
          else:
              print '
  ', filename, 'saved
  '
      except Exception as ex:
          print 'Oups '+str(ex)
      print 'Program ending
  '
  
  #==============================================================================
  if __name__ == "__main__":
      main()