further work on needle valve, pump and lakeshore

frappy_psi/butterflyvalve.py

@@ -0,0 +1,128 @@
+# *****************************************************************************
+#
+# 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>
+#
+# *****************************************************************************
+
+from frappy.core import Attached, Command, EnumType, FloatRange, \
+    Drivable, Parameter, BUSY, IDLE, ERROR
+
+
+class Valve(Drivable):
+    motor = Attached(Drivable)  # refers to motor module
+    value = Parameter('valve state',
+                      EnumType(closed=0, open=1, undefined=2),
+                      default=2)
+    status = Parameter()  # inherit properties from Drivable
+    target = Parameter('valve target',
+                       EnumType(closed=0, open=1),
+                       readonly=False)
+    # TODO: convert to properties after tests
+    open_pos = Parameter('target position for open state', FloatRange(), readonly=False, default=80)
+    mid_pos = Parameter('position for changing speed', FloatRange(), readonly=False, default=5)
+    fast_speed = Parameter('normal speed', FloatRange(), readonly=False, default=40)
+    slow_speed = Parameter('reduced speed', FloatRange(), readonly=False, default=10)
+    __motor_target = None
+    __status = IDLE, ''
+    __value = 'undefined'
+    __drivestate = 0  # 2 when driving to intermediate target or on retry, 1 when driving to final target, 0 when idle
+
+    def doPoll(self):
+        mot = self.motor
+        motpos = mot.read_value()
+        scode, stext = mot.read_status()
+        drivestate = self.__drivestate
+        if scode >= ERROR:
+            if self.__drivestate and self.__remaining_tries > 0:
+                drivestate = 2
+                self.__remaining_tries -= 1
+                mot.reset()
+                mot.write_speed(self.slow_speed)
+                self.__status = BUSY, f'retry {self._action}'
+            else:
+                self.__status = ERROR, f'valve motor: {stext}'
+        elif scode < BUSY:
+            if self.__motor_target is not None and mot.target != self.__motor_target:
+                self.__status = ERROR, 'motor was driven directly'
+            elif drivestate == 2:
+                self.goto(self.target)
+                drivestate = 1
+            else:
+                if -3 < motpos < 3:
+                    self.__value = 'closed'
+                    self.__status = IDLE, ''
+                elif self.open_pos * 0.5 < motpos < self.open_pos * 1.5:
+                    self.__value = 'open'
+                    self.__status = IDLE, ''
+                else:
+                    self.__status = ERROR, 'undefined'
+        if self.__drivestate and not self.isBusy(self.__status):
+            drivestate = 0
+            self.__motor_target = None
+            self.setFastPoll(False)
+        self.__drivestate = drivestate
+        self.read_status()
+        self.read_value()
+
+    def read_status(self):
+        return self.__status
+
+    def read_value(self):
+        if self.read_status()[0] >= BUSY:
+            return 'undefined'
+        return self.__value
+
+    def goto(self, target):
+        """go to open, closed or intermediate position
+
+        the intermediate position is targeted when a speed change is needed
+
+        return 2 when a retry is needed, 1 else
+        """
+        mot = self.motor
+        if target:  # 'open'
+            self._action = 'opening'
+            if True or mot.value > self.mid_pos:
+                mot.write_speed(self.fast_speed)
+                self.__motor_target = mot.write_target(self.open_pos)
+                return 1
+            mot.write_speed(self.slow_speed)
+            self.__motor_target = mot.write_target(self.mid_pos)
+            return 2
+        self._action = 'closing'
+        if mot.value > self.mid_pos * 2:
+            mot.write_speed(self.fast_speed)
+            self.__motor_target = mot.write_target(self.mid_pos)
+            return 2
+        mot.write_speed(self.slow_speed)
+        self.__motor_target = mot.write_target(0)
+        return 1
+
+    def write_target(self, target):
+        self.__remaining_tries = 5
+        self.__drivestate = self.goto(target)
+        self.__status = BUSY, self._action
+        self.read_status()
+        self.read_value()
+        self.setFastPoll(True)
+
+    @Command()  # python decorator to mark it as a command
+    def stop(self):
+        """stop the motor -> value might get undefined"""
+        self.__drivestate = 0
+        self.motor.stop()