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driver for Lakeshore Model 370 resistivity measurement

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- this does not (yet) include temperatures and control loop
- including stringio-server for test purposes

Change-Id: I414ae2e6663bb0773fe60db1798401dfc9dde018
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/22005
Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>
This commit is contained in:
zolliker
2019-12-12 14:36:29 +01:00
parent 07eb252b78
commit cb4874331b
5 changed files with 494 additions and 0 deletions
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secop_psi/ls370res.py Normal file
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#!/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:
# Markus Zolliker <markus.zolliker@psi.ch>
# *****************************************************************************
"""LakeShore Model 370 resistance channel"""
import time
from secop.modules import Module, Readable, Drivable, Parameter, Override, Property, Attached
from secop.metaclass import Done
from secop.datatypes import FloatRange, IntRange, EnumType, BoolType
from secop.stringio import HasIodev
from secop.poller import Poller, REGULAR
import secop.commandhandler
Status = Drivable.Status
class CmdHandler(secop.commandhandler.CmdHandler):
CMDARGS = ['channel']
CMDSEPARATOR = ';'
rdgrng = CmdHandler('rdgrng', 'RDGRNG?%(channel)d', '%d,%d,%d,%d,%d')
inset = CmdHandler('inset', 'INSET?%(channel)d', '%d,%d,%d,%d,%d')
filterhdl = CmdHandler('filt', 'FILTER?%(channel)d', '%d,%d,%d')
scan = CmdHandler('scan', 'SCAN?', '%d,%d')
STATUS_TEXT = {0: ''}
for bit, text in enumerate('CS_OVL VCM_OVL VMIX_OVL R_OVER R_UNDER T_OVER T_UNDER'.split()):
for i in range(1 << bit, 2 << bit):
STATUS_TEXT[i] = text
class StringIO(secop.stringio.StringIO):
identification = [('*IDN?', 'LSCI,MODEL370,.*')]
class Main(HasIodev, Module):
parameters = {
'channel':
Parameter('the current channel', poll=REGULAR, datatype=IntRange(), readonly=False, handler=scan),
'autoscan':
Parameter('whether to scan automatically', datatype=BoolType(), readonly=False, handler=scan),
'pollinterval': Parameter('sleeptime between polls', default=5,
readonly=False,
datatype=FloatRange(0.1, 120),
),
}
pollerClass = Poller
def analyze_scan(self, channel, autoscan):
self.channel, self.autoscan = channel, autoscan
def change_scan(self, new, *args):
return new.channel, new.autoscan
class ResChannel(HasIodev, Readable):
'''temperature channel on Lakeshore 336'''
RES_RANGE = {key: i+1 for i, key in list(
enumerate(mag % val for mag in ['%gmOhm', '%gOhm', '%gkOhm', '%gMOhm']
for val in [2, 6.32, 20, 63.2, 200, 632]))[:-2]}
RES_SCALE = [2 * 10 ** (0.5 * i) for i in range(-7,16)] # RES_SCALE[0] is not used
CUR_RANGE = {key: i + 1 for i, key in list(
enumerate(mag % val for mag in ['%gpA', '%gnA', '%guA', '%gmA']
for val in [1, 3.16, 10, 31.6, 100, 316]))[:-2]}
VOLT_RANGE = {key: i + 1 for i, key in list(
enumerate(mag % val for mag in ['%guV', '%gmV']
for val in [2, 6.32, 20, 63.2, 200, 632]))}
pollerClass = Poller
properties = {
'channel':
Property('the Lakeshore channel', datatype=IntRange(), export=False),
'main':
Attached()
}
parameters = {
'value':
Override(datatype=FloatRange(unit='Ohm')),
'pollinterval':
Override(visibility=3),
'range':
Parameter('reading range', readonly=False,
datatype=EnumType(**RES_RANGE), handler=rdgrng),
'minrange':
Parameter('minimum range for software autorange', readonly=False, default=1,
datatype=EnumType(**RES_RANGE)),
'autorange':
Parameter('autorange', datatype=EnumType(off=0, hard=1, soft=2),
readonly=False, handler=rdgrng, default=2),
'iexc':
Parameter('current excitation', datatype=EnumType(off=0, **CUR_RANGE), readonly=False, handler=rdgrng),
'vexc':
Parameter('voltage excitation', datatype=EnumType(off=0, **VOLT_RANGE), readonly=False, handler=rdgrng),
'enable':
Parameter('is this channel enabled?', datatype=BoolType(), readonly=False, handler=inset),
'pause':
Parameter('pause after channel change', datatype=IntRange(), readonly=False, handler=inset),
'dwell':
Parameter('dwell time with autoscan', datatype=IntRange(), readonly=False, handler=inset),
'filter':
Parameter('filter time', datatype=IntRange(), readonly=False, handler=filterhdl),
}
def startModule(self, started_callback):
self._last_range_change = 0
self._main = self.DISPATCHER.get_module(self.main)
super().startModule(started_callback)
def read_value(self):
if self.channel != self._main.channel:
return Done
result = self.sendRecv('RDGR?%d' % self.channel)
result = float(result)
if self.autorange == 'soft':
now = time.time()
if now > self._last_range_change + self.pause:
rng = int(max(self.minrange, self.range)) # convert from enum to int
if self.status[1] == '':
if abs(result) > self.RES_SCALE[rng]:
if rng < 22:
rng += 1
self.log.info('chan %d: increased range to %.3g' %
(self.channel, self.RES_SCALE[rng]))
else:
lim = 0.2
while rng > self.minrange and abs(result) < lim * self.RES_SCALE[rng]:
rng -= 1
lim -= 0.05 # not more than 4 steps at once
# effectively: <0.16 %: 4 steps, <1%: 3 steps, <5%: 2 steps, <20%: 1 step
if lim != 0.2:
self.log.info('chan %d: lowered range to %.3g' %
(self.channel, self.RES_SCALE[rng]))
elif rng < 22:
rng = min(22, rng + 1)
self.log.info('chan: %d, %s, increased range to %.3g' %
(self.channel, self.status[1], self.RES_SCALE[rng]))
if rng != self.range:
self.write_range(rng)
self._last_range_change = now
return result
def read_status(self):
if self.channel != self._main.channel:
return Done
result = int(self.sendRecv('RDGST?%d' % self.channel))
result &= 0x37 # mask T_OVER and T_UNDER (change this when implementing temperatures instead of resistivities)
statustext = STATUS_TEXT[result]
if statustext:
return [self.Status.ERROR, statustext]
return [self.Status.IDLE, '']
def analyze_rdgrng(self, iscur, exc, rng, autorange, excoff):
if excoff:
self.iexc, self.vexc = 0,0
elif iscur:
self.iexc, self.vexc = exc, 0
else:
self.iexc, self.vexc = 0, exc
if autorange:
self.autorange = 'hard'
else:
if self.autorange == 'hard':
self.autorange = 'soft'
else:
self.autorange = self.autorange
self.range = rng
def change_rdgrng(self, new, iscur, exc, rng, autorange, excoff):
if new.vexc != self.vexc: # in case vext is changed, do not consider iexc
new.iexc = 0
if new.iexc != 0: # we need '!= 0' here, as bool(enum) is always True!
iscur = 1
exc = new.iexc
excoff = 0
elif new.vexc != 0: # we need '!= 0' here, as bool(enum) is always True!
iscur = 0
exc = new.vexc
excoff = 0
else:
excoff = 1
rng = new.range
if new.autorange == 'hard':
autorange = 1
else:
autorange = 0
if new.autorange == 'soft':
if rng < new.minrange:
rng = new.minrange
return iscur, exc, rng, autorange, excoff
def analyze_inset(self, on, dwell, pause, curve, tempco):
self.enabled, self.dwell, self.pause = on, dwell, pause
def change_inset(self, new, on, dwell, pause, curve, tempco):
return new.enable, new.dwell, new.pause, curve, tempco
def analyze_filt(self, on, settle, window):
self.filter = settle if on else 0
def change_filt(self, new, on, settle, window):
if new.filter:
return 1, new.filter, 80 # always use 80% filter
return 0, settle, window