Chanes to close microsoft#537

Adds clock_source and ref_source parameters
Also added a change to the get parser of the lowpass filter setting. The
value 9.9e37 corresponds to infinity but can give problems when sending
it over a port (such as to pyqtgraph).

qcodes/instrument_drivers/tektronix/AWG5014.py

@@ -157,12 +157,20 @@ def __init__(self, name, address, timeout=180, **kwargs):
  vals=vals.Enum('CONT', 'TRIG', 'SEQ', 'GAT'),
  get_parser=self.newlinestripper
  )
- self.add_parameter('ref_clock_source',
- label='Reference clock source',
+ self.add_parameter('clock_source',
+ label='Clock source',
  get_cmd='AWGControl:CLOCk:SOURce?',
  set_cmd='AWGControl:CLOCk:SOURce ' + '{}',
  vals=vals.Enum('INT', 'EXT'),
  get_parser=self.newlinestripper)
+
+ self.add_parameter('ref_source',
+ label='Reference source',
+ get_cmd='SOURce1:ROSCillator:SOURce?',
+ set_cmd='SOURce1:ROSCillator:SOURce ' + '{}',
+ vals=vals.Enum('INT', 'EXT'),
+ get_parser=self.newlinestripper)
+
  self.add_parameter('DC_output',
  label='DC Output (ON/OFF)',
  get_cmd='AWGControl:DC:STATe?',
@@ -332,7 +340,7 @@ def __init__(self, name, address, timeout=180, **kwargs):
  set_cmd=filter_cmd + ' {}',
  vals=vals.Enum(20e6, 100e6, 9.9e37,
  'INF', 'INFinity'),
- get_parser=float)
+ get_parser=self._lowpass_filter_get_parser)
  self.add_parameter('ch{}_DC_out'.format(i),
  label='DC output level channel {}'.format(i),
  unit='V',
@@ -387,6 +395,13 @@ def newlinestripper(self, string):
  else:
  return string
 
+ def _lowpass_filter_get_parser(self, string):
+ if 'E+037\n' in string:
+ val = 'INF'
+ else:
+ val = float(string)
+ return val
+
  # Functions
  def get_all(self, update=True):
  """