HW_NI_AnalogInputToString: Use correct string representations

We need to use the names accepted by the NIDAQ MX operations and functions.
See for example the help for DAQmx_AI_SetupReader.

Author: t-b

Packages/MIES/MIES_DAC-Hardware.ipf

@@ -2238,11 +2238,11 @@ Function/S HW_NI_AnalogInputToString(variable config)
 	endif
 
 	if(config & HW_NI_CONFIG_DIFFERENTIAL)
-		str += "Differential, "
+		str += "Diff, "
 	endif
 
 	if(config & HW_NI_CONFIG_PSEUDO_DIFFERENTIAL)
-		str += "Pseudo Differential, "
+		str += "PDIFF, "
 	endif
 
 	ASSERT(!IsEmpty(str), "Invalid config")