#!/usr/bin/env python # -*- coding: utf-8 -*- # ***************************************************************************** # This program is free software; you can redistribute it and/or modify it under # the terms of the GNU General Public License as published by the Free Software # Foundation; either version 2 of the License, or (at your option) any later # version. # # This program is distributed in the hope that it will be useful, but WITHOUT # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS # FOR A PARTICULAR PURPOSE. See the GNU General Public License for more # details. # # You should have received a copy of the GNU General Public License along with # this program; if not, write to the Free Software Foundation, Inc., # 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA # # Module authors: # Daniel Margineda , Oksana Shliakhtun # ***************************************************************************** """Signal Recovery SR7270: lockin amplifier for AC susceptibility""" from frappy.core import Readable, Parameter, FloatRange, TupleOf, \ HasIO, StringIO, BoolType, EnumType from frappy.errors import RangeError class SR_IO(StringIO): end_of_line = b'\x00' identification = [('ID', r'.*')] # Identification; causes the lock-in amplifier to respond with the number 7270 def communicate(self, cmd): # remove dash from terminator reply = super().communicate(cmd) status = self._conn.readbytes(2, timeout=0.1) # get the 2 status bytes return reply + ';%d;%d' % tuple(status) class XY(HasIO, Readable): value = Parameter('X, Y', datatype=TupleOf(FloatRange(unit='V'), FloatRange(unit='V'))) freq = Parameter('oscill. frequen. control', FloatRange(0.001, 250e3), unit='Hz', readonly=False) amp = Parameter('oscill. amplit. control', FloatRange(0.00, 5), unit='V_rms', readonly=False) range = Parameter('sensitivity value', FloatRange(0.00, 1), unit='V', default=1, readonly=False) autorange = Parameter('autorange_on', EnumType('autorange', off=0, soft=1, hard=2), readonly=False, default=0) sen_range = {name: value + 1 for value, name in enumerate( ['2nV', '5nV', '10nV', '20nV', '50nV', '100nV', '200nV', '500nV', '1uV', '2uV', '5uV', '10uV', '20uV', '50uV', '100uV', '200uV', '500uV', '1mV', '2mV', '5mV', '10mV', '20mV', '50mV', '100mV', '200mV', '500mV', '1V'] )} irange = Parameter('sensitivity index', EnumType('sensitivity index range', sen_range), readonly=False) time_const = {name: value for value, name in enumerate( ['10us', '20us', '50us', '100us', '200us', '500us', '1ms', '2ms', '5ms', '10ms', '20ms', '50ms', '100ms', '200ms', '500ms', '1s', '2s', '5s', '10s', '20s', '50s', '100s', '200s', '500s', '1ks', '2ks', '5ks', '10ks', '20ks', '50ks', '100ks'] )} tc = Parameter('time const. value', FloatRange(0.00005, 100000), unit='s', readonly=False) itc = Parameter('time const. index', EnumType('time const. index range', time_const), readonly=False) nm = Parameter('noise mode on', BoolType(), readonly=False) phase = Parameter('reference phase control', FloatRange(-360, 360), unit='deg', readonly=False) vmode = Parameter('control mode', EnumType(both_grounded=0, A=1, B=2, A_B_diff=3), readonly=False) # filter = Parameter('line frequency filter', unit='Hz') # dac = Parameter('output DAC channel value', datatype=TupleOf(IntRange(1, 4), FloatRange(0.0, 5000, unit='mV')), # readonly=False, initwrite=True, default=(3,0)) # dac = Parameter('output DAC channel value', FloatRange(-10000, 10000, unit='mV'), # readonly=False, initwrite=True, default=0) ioClass = SR_IO def comm(self, cmd): reply, status, overload = self.communicate(cmd).split(';') reply = reply.rstrip('\n') if overload != '0': self.status = (self.Status.WARN, f'overload {overload}') self.status = (self.Status.IDLE, '') return reply def comparison(self, curr_value, new_value, value_dict): c_ind = None # closest index c_diff = None # closets difference for index, value in value_dict.items(): if c_diff is None or abs(new_value - value) < c_diff: c_ind = index c_diff = abs(new_value - value) if abs(curr_value - new_value) < c_diff: return c_ind def read_value(self): reply = self.comm('XY.').split(',') x = float(reply[0]) y = float(reply[1]) if self.autorange == 1: # soft if max(abs(x), abs(y)) >= 0.9 * self.range and self.irange < 27: self.write_irange(self.irange + 1) elif max(abs(x), abs(y)) <= 0.3 * self.range and self.irange > 1: self.write_irange(self.irange - 1) return x, y def read_freq(self): return float(self.comm('OF.')) def write_freq(self, freq): self.comm(f'OF. {freq}') return freq def read_autorange(self): reply = self.comm('AUTOMATIC') # determine hardware autorange if reply == 1: # soft return 2 # hard if self.autorange == 0: # soft return self.autorange # read autorange return self.autorange # off def write_autorange(self, value): if value == 2: # hard self.comm('AS') # put hardware autorange on self.comm('AUTOMATIC. 1') else: self.comm('AUTOMATIC. 0') return value def read_amp(self): return float(self.comm('OA.')) def write_amp(self, amp): self.comm(f'OA. {amp}') return amp def read_irange(self): reply = self.comm('SEN') return int(reply) def write_irange(self, irange): value = int(irange) self.comm(f'SEN {value}') self.read_range() return value def read_range(self): reply = self.comm('SEN.') # range value return float(reply) # def write_range(self, val): # curr_val = self.read_range # curr_idx = self.read_irange # # close_val = None # min_diff = None # # for idx, value in self.sen_range.items(): # diff = abs(value - val) # close_idx = self.comparison(curr_val, value, self.sen_range) # if close_idx ?: # close_val = value # close_idx = close_idx # min_diff = abs(curr_val - close_val) # # return self.comm(f'SEN {close_idx}') def read_nm(self): reply = self.comm('NOISEMODE') return reply def write_nm(self, value): self.comm('NOISEMODE %d' % int(value)) self.read_nm() return value def read_tc(self): reply = self.comm('TC.') return float(reply) def write_tc(self, new_tc): curr_value = self.read_tc() new_value = self.time_const[self.itc] c_ind = self.comparison(curr_value, new_value, self.time_const) if abs(curr_value - new_value) < c_ind: if self.read_nm() == 1 and (5e-4 <= self.time_const[new_tc] <= 1e-2): raise RangeError('Not allowed with noisemode=1') return self.comm(f'TC {new_tc}') def read_itc(self): return int(self.comm('TC')) def write_itc(self, itc): value = int(itc) self.comm(f'TC {value}') self.read_tc() return value # phase and autophase def read_phase(self): reply = self.comm('REFP.') return float(reply) def write_phase(self, value): self.comm(f'REFP {round(1000 * value)}') return self.read_phase() def aphase(self): """auto phase""" self.read_phase() return self.comm('AQN') def read_vmode(self): reply = self.comm('VMODE') return int(reply) def write_vmode(self, vmode): value = int(vmode) self.comm(f'VMODE {value}') return value