diff --git a/lppinstru/discovery.py b/lppinstru/discovery.py
--- a/lppinstru/discovery.py
+++ b/lppinstru/discovery.py
@@ -288,9 +288,11 @@ class Discovery(object):
         self.__libdwf.FDwfAnalogInFrequencyGet(self.__hdwf, byref(f))
         frequency=f.value
         self.__libdwf.FDwfAnalogInBufferSizeSet(self.__hdwf, c_int(cnt))
+        range,enabled = [ch1range,ch2range],[ch1,ch2]
+
         for ch in (0,1):
-            self.__libdwf.FDwfAnalogInChannelEnableSet(self.__hdwf, c_int(ch), c_bool(ch2))
-            self.__libdwf.FDwfAnalogInChannelRangeSet(self.__hdwf, c_int(ch), c_double(ch2range))
+            self.__libdwf.FDwfAnalogInChannelEnableSet(self.__hdwf, c_int(ch), c_bool(enabled[ch]))
+            self.__libdwf.FDwfAnalogInChannelRangeSet(self.__hdwf, c_int(ch), c_double(range[ch]))
             self.__libdwf.FDwfAnalogInChannelFilterSet(self.__hdwf,c_int(ch),filterAverage)
         self.set_analog_in_trigger(trigger)
         self.__libdwf.FDwfAnalogInConfigure(self.__hdwf, c_bool(False), c_bool(True))