Util: Add two conversion function for DA/AD unit string return

Added GetADChannelUnit, GetDAChannelUnit that return the unit string
depending on clamp mode.

Packages/MIES/MIES_MiesUtilities_Conversion.ipf

@@ -270,3 +270,15 @@ Function MapAnaFuncToConstant(anaFunc)
 #endif
 	endswitch
 End
+
+/// @brief returns the unit string for the AD channel depending in clampmode
+threadsafe Function/S GetADChannelUnit(variable clampMode)
+
+	return SelectString(clampMode == V_CLAMP_MODE, "mV", "pA")
+End
+
+/// @brief returns the unit string for the DA channel depending in clampmode
+threadsafe Function/S GetDAChannelUnit(variable clampMode)
+
+	return SelectString(clampMode == V_CLAMP_MODE, "pA", "mV")
+End