fix issue with old reading

- old reading shoould be ignored
- fix channels for CTI7

cfg/ls340_cfg.py

@@ -14,20 +14,20 @@ Mod('T',
     output_module = 'Heater',
     target = Param(max=470),
     io = 'io',
-    channel = 'A',
+    channel = 'B',
 )
 
 Mod('T_cold_finger',
     'frappy_psi.lakeshore.Sensor340',
     'cold finger temperature',
     io = 'io',
-    channel = 'B'
+    channel = 'A'
 )
 
 Mod('Heater',
     'frappy_psi.lakeshore.HeaterOutput',
     'heater output',
-    channel = 'A',
+    channel = 'B',
     io = 'io',
     resistance = 50,
     max_power = 50,

frappy_psi/lakeshore.py

@@ -58,9 +58,8 @@ class Sensor340(HasIO, Readable):
             return ERROR, 'temperature overrange'
         if c >= 16:
             return ERROR, 'temperature underrange'
-        if c >= 2:
-            return ERROR, 'old reading'
-        if c >= 1:
+        # do not check for old reading -> this happens regularely on NTCs with T comp
+        if c % 2:
             return ERROR, 'invalid reading'
         return IDLE, ''