Markus Zolliker
da15df076a
- before some chamges in the gerrit pipline Change-Id: I33eb2d75f83345a7039d0fb709e66defefb1c3e0
93 lines
3.4 KiB
Python
93 lines
3.4 KiB
Python
#!/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>
|
|
# *****************************************************************************
|
|
"""Andeen Hagerling capacitance bridge"""
|
|
|
|
from frappy.core import FloatRange, HasIO, Parameter, Readable, StringIO, nopoll
|
|
|
|
|
|
class Ah2700IO(StringIO):
|
|
end_of_line = '\r\n'
|
|
timeout = 5
|
|
|
|
|
|
class Capacitance(HasIO, Readable):
|
|
|
|
value = Parameter('capacitance', FloatRange(unit='pF'))
|
|
freq = Parameter('frequency', FloatRange(unit='Hz'), readonly=False, default=0)
|
|
voltage = Parameter('voltage', FloatRange(unit='V'), readonly=False, default=0)
|
|
loss = Parameter('loss', FloatRange(unit='deg'), default=0)
|
|
|
|
ioClass = Ah2700IO
|
|
|
|
def parse_reply(self, reply):
|
|
if reply.startswith('SI'): # this is an echo
|
|
self.communicate('SERIAL ECHO OFF')
|
|
reply = self.communicate('SI')
|
|
if not reply.startswith('F='): # this is probably an error message like "LOSS TOO HIGH"
|
|
self.status = [self.Status.ERROR, reply]
|
|
return self.value
|
|
self.status = [self.Status.IDLE, '']
|
|
# examples of replies:
|
|
# 'F= 1000.0 HZ C= 0.000001 PF L> 0.0 DS V= 15.0 V'
|
|
# 'F= 1000.0 HZ C= 0.0000059 PF L=-0.4 DS V= 15.0 V OVEN'
|
|
# 'LOSS TOO HIGH'
|
|
# make sure there is always a space after '=' and '>'
|
|
# split() ignores multiple white space
|
|
reply = reply.replace('=', '= ').replace('>', '> ').split()
|
|
_, freq, _, _, cap, _, _, loss, lossunit, _, volt = reply[:11]
|
|
self.freq = freq
|
|
self.voltage = volt
|
|
if lossunit == 'DS':
|
|
self.loss = loss
|
|
else: # the unit was wrong, we want DS = tan(delta), not NS = nanoSiemens
|
|
reply = self.communicate('UN DS').split() # UN DS returns a reply similar to SI
|
|
try:
|
|
self.loss = reply[7]
|
|
except IndexError:
|
|
pass # don't worry, loss will be updated next time
|
|
return cap
|
|
|
|
def read_value(self):
|
|
return self.parse_reply(self.communicate('SI')) # SI = single trigger
|
|
|
|
@nopoll
|
|
def read_freq(self):
|
|
self.read_value()
|
|
return self.freq
|
|
|
|
@nopoll
|
|
def read_loss(self):
|
|
self.read_value()
|
|
return self.loss
|
|
|
|
@nopoll
|
|
def read_voltage(self):
|
|
self.read_value()
|
|
return self.voltage
|
|
|
|
def write_freq(self, value):
|
|
self.value = self.parse_reply(self.communicate(f'FR {value:g};SI'))
|
|
return self.freq
|
|
|
|
def write_voltage(self, value):
|
|
self.value = self.parse_reply(self.communicate(f'V {value:g};SI'))
|
|
return self.voltage
|