main module of LS370 is now drivable

- the main value is the channel
- it is busy when pausing during scanning
+ allow softcal to ignore the sign

secop_psi/ls370res.py

@@ -21,7 +21,6 @@
 """LakeShore Model 370 resistance channel"""
 
 import time
-import json
 
 from secop.modules import Readable, Drivable, Parameter, Override, Property, Attached
 from secop.metaclass import Done
@@ -85,7 +84,11 @@ class Main(HasIodev, Drivable):
                 self.sendRecv('INSET %d,0,0,0,0,0;INSET?%d' % (ch, ch))
 
     def read_value(self):
-        channel, auto = json.loads('[%s]' % self.sendRecv('SCAN?'))
+        channel, auto = scan.send_command(self)
+        # response = self.sendRecv('SCAN?').strip().split(',')
+        # channel, auto = (int(s) for s in response)
+        if channel not in self._channels:
+           return channel
         if not self._channels[channel].enabled:
             # channel was disabled recently, but still selected
             nextchannel = 0
@@ -96,13 +99,12 @@ class Main(HasIodev, Drivable):
                         break
                     if nextchannel == 0:
                         nextchannel = ch
-            if not nextchannel:
+            if nextchannel:
                 self.write_target(nextchannel)
                 return 0
 
         now = time.time()
         if channel != self.target:
-            print('changed' , channel, self.target)
             self._channel_changed = now
             self.target = channel
         self.autoscan = int(auto)
@@ -113,7 +115,8 @@ class Main(HasIodev, Drivable):
         return channel
 
     def write_target(self, channel):
-        self.sendRecv('SCAN %d,%d;SCAN?' % (channel, self.autoscan))
+        scan.send_change(self, channel, self.autoscan)
+        # self.sendRecv('SCAN %d,%d;SCAN?' % (channel, self.autoscan))
         if channel != self.value:
             self.value = 0
             self._channel_changed = time.time()