dummy_cfg.py: add test case with big enum

+ fix undefined value in frappy_psi.ls370res.Switcher

Change-Id: I59f2814b945533c487999f9af638e0fb2040e862

cfg/dummy_cfg.py

@@ -108,3 +108,29 @@ Mod('bool',
     'frappy_demo.modules.BoolWritable',
     'boolean writable test',
 )
+
+Mod('lscom',
+    'frappy_psi.ls370sim.Ls370Sim',
+    'simulated serial communicator to a LS 370',
+    visibility = 3
+)
+
+Mod('sw',
+    'frappy_psi.ls370res.Switcher',
+    'channel switcher for Lsc controller',
+    io = 'lscom',
+)
+
+Mod('a',
+    'frappy_psi.ls370res.ResChannel',
+    'resistivity',
+    channel = 1,
+    switcher = 'sw',
+)
+
+Mod('b',
+    'frappy_psi.ls370res.ResChannel',
+    'resistivity',
+    channel = 3,
+    switcher = 'sw',
+)

frappy_psi/ls370res.py

@@ -166,6 +166,7 @@ class Switcher(LakeShoreIO, ChannelSwitcher):
 
     def set_active_channel(self, chan):
         self.set_param('SCAN ', chan.channel, 0)
+        self.value = chan.channel
         chan._last_range_change = time.monotonic()
         self.set_delays(chan)