drivers for AH700 and K2601B

AH2700: Andeen Hagerling capacitance bridge

This is a use case for 'return Done' in read_<parameter>

K2601b: Keithley source meter

Current and Source are two dependend SECoP modules: only
one of them might be active. Writing to target is allowed only
when active, but both values are always readable.
A common SourceMeter bare Module is present for common functionality.

Change-Id: I6f1875298ef928bcc2d60b89560b837139160775
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/22071
Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

cfg/ah2700test.cfg

@@ -0,0 +1,17 @@
+[node AH2700Test.psi.ch]
+description = AH2700 capacitance bridge test
+
+[interface tcp]
+type = tcp
+bindto = 0.0.0.0
+bindport = 5000
+
+[module cap]
+class = secop_psi.ah2700.Capacitance
+description = capacitance
+uri=ldmse3-ts:3015
+
+#[module ahcom]
+#class = secop_psi.ah2700.StringIO
+#uri=ldmse3-ts:3015
+#description = serial communicator to an AH2700

secop_psi/ah2700.py

@@ -0,0 +1,80 @@
+#!/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 secop import Readable, Parameter, Override, FloatRange, HasIodev, StringIO, Done
+
+
+class Ah2700IO(StringIO):
+    end_of_line = '\r\n'
+    timeout = 5
+
+
+class Capacitance(HasIodev, Readable):
+    parameters = {
+        'value': Override('capacitance', FloatRange(unit='pF'), poll=True),
+        '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'), readonly=False, default=0),
+    }
+    iodevClass = Ah2700IO
+
+    def read_value(self):
+        reply = self.sendRecv('SI')  # single trigger
+        if reply.startswith('SI'):  # this is an echo
+            self.sendRecv('SERIAL ECHO OFF')
+            reply = self.sendRecv('SI')
+        if not reply.startswith('F='):  # this is probably an error message like "LOSS TOO HIGH"
+            self.status = [self.Status.ERROR, reply]
+            return Done
+        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
+        self.value = cap
+        if lossunit == 'DS':
+            self.loss = loss
+        else:  # the unit was wrong, we want DS = tan(delta), not NS = nanoSiemens
+            reply = self.sendRecv('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 Done
+
+    def read_freq(self):
+        self.read_value()
+        return Done
+
+    def read_loss(self):
+        self.read_value()
+        return Done
+
+    def read_volt(self):
+        self.read_value()
+        return Done

secop_psi/k2601b.py

@@ -0,0 +1,165 @@
+#!/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>
+# *****************************************************************************
+"""Keithley 2601B source meter
+
+not tested yet"""
+
+from secop import Writable, Module, Parameter, Override, Attached,\
+    BoolType, FloatRange, EnumType, HasIodev, StringIO
+
+
+class K2601bIO(StringIO):
+    identification = [('print(localnode.description)', 'Keithley Instruments SMU 2601B.*')]
+
+
+SOURCECMDS = {
+    1: 'reset()'
+       'smua.source.func = smua.OUTPUT_DCVOLTS '
+       'display.smua.measure.func = display.MEASURE_DCAMP '
+       'smua.source.autorangev = 1',
+    2: 'reset()'
+       'smua.source.func = smua.OUTPUT_DCAMPS '
+       'smua.source.autorangei = 1',
+}
+
+
+class SourceMeter(HasIodev, Module):
+    parameters = {
+        'resistivity': Parameter('readback resistivity', FloatRange(unit='Ohm'), poll=True),
+        'power': Parameter('readback power', FloatRange(unit='W'), poll=True),
+        'mode': Parameter('measurement mode', EnumType(off=0, current=1, voltage=2),
+                          readonly=False, default=0),
+        'active': Parameter('output enable', BoolType(), readonly=False, poll=True),
+    }
+    iodevClass = K2601bIO
+
+    def read_resistivity(self):
+        return self.sendRecv('print(smua.measure.r())')
+
+    def read_power(self):
+        return self.sendRecv('print(smua.measure.p())')
+
+    def read_active(self):
+        return self.sendRecv('print(smua.source.output)')
+
+    def write_active(self, value):
+        return self.sendRecv('smua.source.output = %d print(smua.source.output)' % value)
+
+    # for now, mode will not be read from hardware
+
+    def write_mode(self, value):
+        if value == 0:
+            self.write_active(0)
+        else:
+            self.sendRecv(SOURCECMDS[value] + ' print(0)')
+        return value
+
+
+class Current(HasIodev, Writable):
+    properties = {
+        'sourcemeter': Attached(),
+    }
+    parameters = {
+        'value': Override('measured current', FloatRange(unit='A'), poll=True),
+        'target': Override('set current', FloatRange(unit='A'), poll=True),
+        'active': Parameter('current is controlled', BoolType(), default=False),  # polled from Current/Voltage
+        'limit': Parameter('current limit', FloatRange(0, 2.0, unit='A'), default=2, poll=True),
+    }
+
+    def read_value(self):
+        return self.sendRecv('print(smua.measure.i())')
+
+    def read_target(self):
+        return self.sendRecv('print(smua.source.leveli)')
+
+    def write_target(self, value):
+        if not self.active:
+            raise ValueError('current source is disabled')
+        if value > self.limit:
+            raise ValueError('current exceeds limit')
+        return self.sendRecv('smua.source.leveli = %g print(smua.source.leveli)' % value)
+
+    def read_limit(self):
+        if self.active:
+            return self.limit
+        return self.sendRecv('print(smua.source.limiti)')
+
+    def write_limit(self, value):
+        if self.active:
+            return value
+        return self.sendRecv('smua.source.limiti = %g print(smua.source.limiti)' % value)
+
+    def read_active(self):
+        return self._sourcemeter.mode == 1 and self._sourcemeter.read_active()
+
+    def write_active(self, value):
+        if self._sourcemeter.mode != 1:
+            if value:
+                self._sourcemeter.write_mode(1)  # switch to current
+            else:
+                return 0
+        return self._sourcemeter.write_active(value)
+
+
+class Voltage(HasIodev, Writable):
+    properties = {
+        'sourcemeter': Attached(),
+    }
+    parameters = {
+        'value': Override('measured voltage', FloatRange(unit='V'), poll=True),
+        'target': Override('set voltage', FloatRange(unit='V'), poll=True),
+        'active': Parameter('voltage is controlled', BoolType(), poll=True),
+        'limit': Parameter('current limit', FloatRange(0, 2.0, unit='V'), default=2, poll=True),
+    }
+
+    def read_value(self):
+        return self.sendRecv('print(smua.measure.v())')
+
+    def read_target(self):
+        return self.sendRecv('print(smua.source.levelv)')
+
+    def write_target(self, value):
+        if not self.active:
+            raise ValueError('voltage source is disabled')
+        if value > self.limit:
+            raise ValueError('voltage exceeds limit')
+        return self.sendRecv('smua.source.levelv = %g print(smua.source.levelv)' % value)
+
+    def read_limit(self):
+        if self.active:
+            return self.limit
+        return self.sendRecv('print(smua.source.limitv)')
+
+    def write_limit(self, value):
+        if self.active:
+            return value
+        return self.sendRecv('smua.source.limitv = %g print(smua.source.limitv)' % value)
+
+    def read_active(self):
+        return self._sourcemeter.mode == 2 and self._sourcemeter.read_active()
+
+    def write_active(self, value):
+        if self._sourcemeter.mode != 2:
+            if value:
+                self._sourcemeter.write_mode(2) # switch to voltage
+            else:
+                return 0
+        return self._sourcemeter.write_active(value)