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Fix: Keithley 2000 modes #334

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merged 11 commits into from
Sep 20, 2016
Merged

Fix: Keithley 2000 modes #334

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4d99ada
workaround for termination character issues
Jul 22, 2016
de2b33e
fix version command; fix issue with expected_answer_length
Jul 22, 2016
1afa449
make sure termination characters are ignored
Jul 22, 2016
9241958
fix: Mode-dependent parameters
Rubenknex Sep 16, 2016
8a566f5
refactor: PEP8 formatting
Rubenknex Sep 16, 2016
82946cc
Revert "make sure termination characters are ignored"
Rubenknex Sep 16, 2016
1312c1b
Revert "fix version command; fix issue with expected_answer_length"
Rubenknex Sep 16, 2016
b73933e
Revert "workaround for termination character issues"
Rubenknex Sep 16, 2016
79a3815
fix: typos in triggering check
Rubenknex Sep 19, 2016
0f62b74
refactor: bool type check
Rubenknex Sep 20, 2016
707f98d
fix: newline char handling
Rubenknex Sep 20, 2016
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103 changes: 66 additions & 37 deletions qcodes/instrument_drivers/tektronix/Keithley_2000.py
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Original file line number Diff line number Diff line change
@@ -1,8 +1,9 @@
from qcodes import VisaInstrument
from qcodes.utils.validators import Numbers, Ints, Enum, MultiType
from qcodes.utils.validators import Numbers, Ints, Enum, MultiType, Bool

from functools import partial


def parse_output_string(s):
""" Parses and cleans string outputs of the Keithley """
# Remove surrounding whitespace and newline characters
Expand All @@ -25,90 +26,110 @@ def parse_output_string(s):

return s


def parse_output_bool(value):
return 'on' if int(value) == 1 else 'off'
return True if int(value) == 1 else False


class Keithley_2000(VisaInstrument):
"""
Driver for the Keithley 2000 multimeter.
"""
def __init__(self, name, address, reset=False, **kwargs):
super().__init__(name, address, **kwargs)
super().__init__(name, address, terminator='\n', **kwargs)

self._trigger_sent = False

# Unfortunately the strings have to contain quotation marks and a
# newline character, as this is how the instrument returns it.
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Pass the terminator='\n' along to super().__init__ (in fact, perhaps only there, there's probably no reason to put it in the K2000 constructor is there?) and pyvisa will take out the newlines for you.

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Maybe this is expected behavior, but when using a val_mapping the newline doesn't get chopped off. As evidenced by the usage in the constructor and the fact that the current _mode_map works.

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it's in the signature of this constructor, but you don't do anything with it after that. But if you instead put it in the super().__init__ call, it really should take the newlines out.

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See for example the K2600 driver

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Ah I see... didn't think of adding it to the super() call.

self._mode_map = {
'ac current': '"CURR:AC"',
'dc current': '"CURR:DC"',
'ac voltage': '"VOLT:AC"',
'dc voltage': '"VOLT:DC"',
'2w resistance': '"RES"',
'4w resistance': '"FRES"',
'temperature': '"TEMP"',
'frequency': '"FREQ"',
}

self.add_parameter('mode',
get_cmd='SENS:FUNC?',
set_cmd="SENS:FUNC {}",
val_mapping={
'ac current': '"CURR:AC"\n',
'dc current': '"CURR:DC"\n',
'ac voltage': '"VOLT:AC"\n',
'dc voltage': '"VOLT:DC"\n',
'2w resistance': '"RES"\n',
'4w resistance': '"FRES"\n',
'temperature': '"TEMP"\n',
'frequency': '"FREQ"\n',
})
val_mapping=self._mode_map)

# Mode specific parameters
self.add_parameter('nplc',
get_cmd=partial(self._get_mode_param, 'NPLC', float),
get_cmd=partial(self._get_mode_param, 'NPLC',
float),
set_cmd=partial(self._set_mode_param, 'NPLC'),
vals=Numbers(min_value=0.01, max_value=10))

# TODO: validator, this one is more difficult since different modes
# require different validation ranges
self.add_parameter('range',
get_cmd=partial(self._get_mode_param, 'RANG', float),
get_cmd=partial(self._get_mode_param, 'RANG',
float),
set_cmd=partial(self._set_mode_param, 'RANG'),
vals=Numbers())

self.add_parameter('auto_range',
get_cmd=partial(self._get_mode_param, 'RANG:AUTO', parse_output_bool),
self.add_parameter('auto_range_enabled',
get_cmd=partial(self._get_mode_param, 'RANG:AUTO',
parse_output_bool),
set_cmd=partial(self._set_mode_param, 'RANG:AUTO'),
vals=Enum('on', 'off'))
vals=Bool())

self.add_parameter('digits',
get_cmd=partial(self._get_mode_param, 'DIG', int),
set_cmd=partial(self._set_mode_param, 'DIG'),
vals=Ints(min_value=4, max_value=7))

self.add_parameter('averaging_type',
get_cmd=partial(self._get_mode_param, 'AVER:TCON', parse_output_string),
get_cmd=partial(self._get_mode_param, 'AVER:TCON',
parse_output_string),
set_cmd=partial(self._set_mode_param, 'AVER:TCON'),
vals=Enum('moving', 'repeat'))

self.add_parameter('averaging_count',
get_cmd=partial(self._get_mode_param, 'AVER:COUN', int),
get_cmd=partial(self._get_mode_param, 'AVER:COUN',
int),
set_cmd=partial(self._set_mode_param, 'AVER:COUN'),
vals=Ints(min_value=1, max_value=100))

self.add_parameter('averaging',
get_cmd=partial(self._get_mode_param, 'AVER:STAT', parse_output_bool),
self.add_parameter('averaging_enabled',
get_cmd=partial(self._get_mode_param, 'AVER:STAT',
parse_output_bool),
set_cmd=partial(self._set_mode_param, 'AVER:STAT'),
vals=Enum('on', 'off'))
vals=Bool())

# Global parameters
self.add_parameter('display',
self.add_parameter('display_enabled',
get_cmd='DISP:ENAB?',
get_parser=parse_output_bool,
set_cmd='DISP:ENAB {}',
vals=Enum('on', 'off'))
set_parser=int,
vals=Bool())

self.add_parameter('trigger_continuous',
get_cmd='INIT:CONT?',
get_parser=parse_output_bool,
set_cmd='INIT:CONT {}',
vals=Enum('on', 'off'))
set_parser=int,
vals=Bool())

self.add_parameter('trigger_count',
get_cmd='TRIG:COUN?',
get_parser=int,
set_cmd='TRIG:COUN {}',
vals=MultiType(Ints(min_value=1, max_value=9999), Enum('inf')))
vals=MultiType(Ints(min_value=1, max_value=9999),
Enum('inf',
'default',
'minimum',
'maximum')))

self.add_parameter('trigger_delay',
get_cmd='TRIG:DEL?',
get_parser=float,
set_cmd='TRIG:DEL {}',
units='s',
vals=Numbers(min_value=0, max_value=999999.999))
Expand All @@ -117,15 +138,16 @@ def __init__(self, name, address, reset=False, **kwargs):
get_cmd='TRIG:SOUR?',
set_cmd='TRIG:SOUR {}',
val_mapping={
'immediate': 'IMM\n',
'timer': 'TIM\n',
'manual': 'MAN\n',
'bus': 'BUS\n',
'external': 'EXT\n',
'immediate': 'IMM',
'timer': 'TIM',
'manual': 'MAN',
'bus': 'BUS',
'external': 'EXT',
})

self.add_parameter('trigger_timer',
get_cmd='TRIG:TIM?',
get_parser=float,
set_cmd='TRIG:TIM {}',
units='s',
vals=Numbers(min_value=0.001, max_value=999999.999))
Expand All @@ -142,25 +164,32 @@ def __init__(self, name, address, reset=False, **kwargs):
self.connect_message()

def trigger(self):
if self.trigger_continuous() == 'off':
if not self.trigger_continuous():
self.write('INIT')
self._trigger_sent = True

def _read_next_value(self):
# Prevent a timeout when no trigger has been sent
if self.trigger_continuous() == 'off' and not self._trigger_sent:
if not self.trigger_continuous() and not self._trigger_sent:
return 0.0

self._trigger_sent = False

return float(self.ask('DATA:FRESH?'))

def _get_mode_param(self, parameter, parser):
cmd = '{}:{}?'.format(self.mode(), parameter)
""" Read the current Keithley mode and ask for a parameter """
mode = parse_output_string(self._mode_map[self.mode()])
cmd = '{}:{}?'.format(mode, parameter)

return parser(self.ask(cmd))

def _set_mode_param(self, parameter, value):
cmd = '{}:{} {}'.format(self.mode(), parameter, value)
""" Read the current Keithley mode and set a parameter """
if isinstance(value, bool):
value = int(value)

mode = parse_output_string(self._mode_map[self.mode()])
cmd = '{}:{} {}'.format(mode, parameter, value)

self.write(cmd)
self.write(cmd)