What SCPI command will return the number of channels on Agilent series E3630 power suplies

[skinned_knuckles]

I have 6 Agilent series E3630 power supplies all connected to my test system via GPIB interface.  Most are single channel but some have 2 channels and some have 3 channels.  My program needs to identify the channel capabilities of each power supply at run time.  I have been using INST:NSEL n for n = 1 to whatever until no new channels are detected but if I write INST:NSEL 3 to a power supply that only has 2 channels I get the error -222,"Data out of range"  So really what I need is to know the number of channels before I begin to query about their output capabilities.  Isn't there some command that will return the number of channels for a given power supply?  FYI I am not using Labview, Visa, IVI, measurement studio or anything like that.  I simply send commands with the NationalInstruments.NI4882 dll. 

[smercurio_fc]

There was a similar question asked just this week. As noted, if you have an IVI driver then you should be able to do it. If you don't, and if the power supply doesn't have a command to do this in its programming manual (SCPI or otherwise), then you will need to have some sort of table that you can lookup based on the model number of the power supply.