frappy_psi.ls370res: add TemperatureChannel

Change-Id: I5a0fd6a1352f08583393862718f59ee5fb6eee32

frappy_psi/ls370res.py

@@ -34,6 +34,8 @@ from frappy.lib import formatStatusBits
 from frappy.core import Done, Drivable, Parameter, Property, CommonReadHandler, CommonWriteHandler
 from frappy.io import HasIO
 from frappy_psi.channelswitcher import Channel, ChannelSwitcher
+from frappy_psi.picontrol import HasConvergence
+
 
 Status = Drivable.Status
 
@@ -209,6 +211,7 @@ class ResChannel(LakeShoreIO, Channel):
     _last_range_change = 0
     rdgrng_params = 'range', 'iexc', 'vexc'
     inset_params = 'enabled', 'pause', 'dwell'
+    STATUS_MASK = 0x37
 
     def initModule(self):
         # take io from switcher
@@ -222,7 +225,7 @@ class ResChannel(LakeShoreIO, Channel):
         if not self.channel == self.switcher.value == self.switcher.target:
             return Done
         result = self.get_param(f'RDGST?{self.channel}')
-        result &= 0x37  # mask T_OVER and T_UNDER (change this when implementing temperatures instead of resistances)
+        result &= self.STATUS_MASK  # mask T_OVER and T_UNDER
         statustext = ' '.join(formatStatusBits(result, STATUS_BIT_LABELS))
         if statustext:
             return [self.Status.ERROR, statustext]
@@ -344,3 +347,19 @@ class ResChannel(LakeShoreIO, Channel):
         if not on:
             settle = 0
         return settle
+
+
+class TemperatureChannel(ResChannel):
+    raw = Parameter('raw resistance value', FloatRange(unit='Ohm'))
+    value = Parameter('temperature sensor', FloatRange(0, unit='K'))
+    STATUS_MASK = 0xff  # accept T_OVER and T_UNDER
+
+    def read_raw(self):
+        if self.channel == self.switcher.value == self.switcher.target:
+            return self._read_value() or self.raw
+        return self.raw or 0
+
+    def read_value(self):
+        if self.channel == self.switcher.value == self.switcher.target:
+            return float(self.communicate('RDGK?%d' % self.channel))
+        return self.value if self.enabled else 0