uniax: added force control as seperate module

Change-Id: I8b14fc90f5885834e342f6bc5e5dd0ea711b27ea

secop_psi/simdpm.py

@@ -0,0 +1,42 @@
+#  -*- 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:
+#   M. Zolliker <markus.zolliker@psi.ch>
+#
+# *****************************************************************************
+"""simulated transducer DPM3 read out"""
+
+import random
+from secop.core import Readable, Parameter, FloatRange, Attached
+from secop.lib import clamp
+
+
+class DPM3(Readable):
+    motor = Attached()
+    jitter = Parameter('simulated jitter', FloatRange(unit='N'), default=1, readonly=False)
+    hysteresis = Parameter('simulated hysteresis', FloatRange(unit='deg'), default=100, readonly=False)
+    friction = Parameter('friction', FloatRange(unit='N/deg'), default=1, readonly=False)
+    slope = Parameter('slope', FloatRange(unit='N/deg'), default=10, readonly=False)
+
+    _pos = 0  # effective piston position, main hysteresis taken into account
+
+    def read_value(self):
+        mot = self._motor
+        self._pos = clamp(self._pos, mot.value - self.hysteresis * 0.5, mot.value + self.hysteresis * 0.5)
+        return clamp(0, 1, mot.value - self._pos) * self.friction \
+               + self._pos * self.slope + self.jitter * (random.random() - random.random())