76 lines
2.6 KiB
Python
76 lines
2.6 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
|
|
# *****************************************************************************
|
|
"""Nanovoltmeter Keithley 2182A"""
|
|
import time
|
|
from frappy.core import FloatRange, HasIO, Module, Parameter, StringIO, Readable, Property, IntRange, Done
|
|
|
|
|
|
class NanovIO(StringIO):
|
|
channel = Parameter('active channel nr', IntRange(0, 16), default=0, readonly=False)
|
|
_channel_index = -1
|
|
end_of_line = '\n'
|
|
_last_change = 0
|
|
_channels = None
|
|
pollinterval = 1
|
|
|
|
def earlyInit(self):
|
|
super().earlyInit()
|
|
self._channels = []
|
|
|
|
def register(self, channel):
|
|
if channel not in self._channels:
|
|
self._channels.append(channel)
|
|
|
|
def doPoll(self):
|
|
try:
|
|
idx = self._channel_index
|
|
channel = self._channels[idx]
|
|
reply = float(self.communicate('FETCH?'))
|
|
if abs(reply) > 1000:
|
|
self.log.warning('bad reply: %s', reply)
|
|
return
|
|
channel.value = float(reply)
|
|
except IndexError:
|
|
idx = -1
|
|
now = time.time()
|
|
if now < self._last_change + 5 or (idx >= 0 and len(self._channels) == 1):
|
|
return
|
|
self._last_change = now
|
|
self._channel_index = idx = (idx + 1) % len(self._channels)
|
|
self.channel = self._channels[idx].channel
|
|
self.communicate(';SENS:CHAN %i;:SENS:CHAN?' % self.channel)
|
|
|
|
|
|
class Volt(HasIO, Readable):
|
|
channel = Property('channel', datatype=IntRange(1, 16))
|
|
value = Parameter('Voltage1', FloatRange(unit='V'))
|
|
|
|
ioClass = NanovIO
|
|
|
|
def initModule(self):
|
|
super().initModule()
|
|
self.io.register(self)
|
|
|
|
def read_value(self):
|
|
if self.io.channel == self.channel:
|
|
self.io.doPoll() # trigger read
|
|
return Done
|