"""Gain and time constant commands"""
from .sr850_driver import SR850Driver
[docs]class SR850GainTime(SR850Driver):
"""Gain and time constant commands"""
[docs] def sens(self, sensitivity):
"""Sets sensitivity"""
cmd = ["2 nV/fA", "5 nV/fA", "10 nV/fA", "20 nV/fA", "50 nV/fA",
"100 nV/fA", "200 nV/fA", "500 nV/fA", "1 microV/pA", "2 microV/pA",
"5 microV/pA", "10 microV/pA", "20 microV/pA", "50 microV/pA",
"100 microV/pA", "200 microV/pA", "500 microV/pA", "1 mV/nA",
"2 mV/nA", "5 mV/nA", "10 mV/nA", "20 mV/nA", "50 mV/nA", "100 mV/nA",
"200 mV/nA", "500 mV/nA", "1 V/microA"]
if sensitivity is None:
setting = int(self._query('SENS?'))
try:
ret = cmd[setting]
except IndexError:
ret = 'unknown value: {}'.format(setting)
return ret
for num, val in enumerate(cmd):
if val == sensitivity:
self._set('SENS {}'.format(num))
break
else:
raise ValueError('invalid sensitivity value: {}'.format(sensitivity))
[docs] def rmod(self, mode=None):
"""Sets or queries reserve mode."""
cmd = ['Max', 'Manual', 'Min']
if mode is None:
setting = int(self._query('RMOD?'))
try:
ret = cmd[setting]
except IndexError:
ret = 'unknown value: {}'.format(setting)
return ret
if mode == 0:
return 'Max'
elif mode == 1:
return 'Manual'
elif mode == 2:
return 'Min'
else:
raise ValueError('invalid mode value: {}'.format(mode))
[docs] def rsrv(self, reserve=None):
"""Sets or queries dynamic reserve.
Sets or queries dynamic reserve to i^(th) available reserve (between 0 and 5).
Must be in Manual reserve mode
0 (minimum reserve for present sensitivity and time constant
1 (next highest reserve)
...
5 (always sets reserve to max.)
Reserve increases by 10 dB for each successive value of i.
"""
if self.rmod() != 'Manual':
raise RuntimeError("dynamic reserve can only be used when " +
"the reserve mode is set to 'Manual'")
if reserve is None:
return int(self._query('RSRV?'))
if 0 <= reserve <= 5:
self._set('RSRV {}'.format(reserve))
else:
raise ValueError('invalid reserve value: {}'.format(reserve))
[docs] def oflt(self, timeconst=None):
"""Sets time constant."""
constants = ['10us', '30us', '100us', '300us', '1ms',
'3ms', '10ms', '30ms', '100ms', '300ms',
'1s', '3s', '10s', '30s', '100s', '300s',
'1ks', '3ks', '10ks', '30ks']
if timeconst is None:
return constants[int(self._query('OFLT?'))]
self._set('OFLT {}'.format(constants.index(timeconst)))
[docs] def ofsl(self, slope=None):
"""Sets low pass filter slope."""
constants = ['6 dB/oct', '12 dB/oct', '18 dB/oct', '24 dB/oct']
if slope is None:
return constants[int(self._query('OFSL?'))]
self._set('OFSL {}'.format(constants.index(slope)))
[docs] def sync(self, filter_status=None):
"""Sets synchronous filter status.
Only turned on if detection frequency < 200 Hz.
* 0 (off)
* 1 (synchronous filter below 200 Hz)
"""
constants = ['off', 'synchronous filter below 200 Hz']
if filter_status is None:
return constants[int(self._query('SYNC?'))]
self._set('SYNC {}'.format(constants.index(filter_status)))
