How to add a channel with session based interface?

I'm trying to get an analog output with my NI-USB-6501 D/A device to control an other device. I've got the Data Acquisition Toolbox with 64bit Matlab R2011a running on Windows 7 .

First I tried to add or connect the device somehow with Matlab:

daqfind
ans = 
  []

what were'n very succesfull. Then I tried:

 s=daq.createsession('ni')
s=
Data acquisition session using National Instruments hardware:
Will run for 1 second (1000)scans at 1000 scans/second.
No channels have been added.

Next i wanted to add a channel. That's were my problems have started. With the 64bit version i must use the session-based interface, that's propably why this doesn't work

dio=digitalio('nidaq', 'Dev1')

So i tried

s.addAnalogOutputChannel('Dev1','ao2','Voltage')

    and

ch=s.addAnalogOutputChannel('Dev1','ao2','Voltage')

but that all doesn't work at all. It answers:

    ???No appropriate method, property, or field addanalogoutputchannel for class daq.ni.session.

Im not sure wether I used the right deviceID, channelID and measurementType in

s.addAnalogOutputChannel(deviceID, channelID, measurementType)

Thanks in advance! Patrick

Answer 1

[Friedrich]

Hi,

it seems more like a programming mistake on your end. MATLAB is Case sensitive. Make sure you use the correct syntax:

>> s.addanalogoutputchannel 
No appropriate method, property, or field addanalogoutputchannel for class
daq.ni.Session.

>> s.addAnalogOutputChannel
Adding a channel requires a device ID, a channel ID, and a measurement type.

The first call is most likely what you did (at least thats what the error message you get suggests), which will fail because the method name is wrong.

[Patrick]

Now I've got another problem.

s.addAnalogOutputChannel('Dev1','ao1','Voltage')

gives out:

??? There are no CompactDAQ devices available. So I tried to search/find my devices...

If I type in:

daq.getVendors

Matlab answers correctly with informations as ID, FullName, Adaptor Version etc.

But if I try :

daq.getDevices
ans = 
No data acquisition devices available

The Matlabs help function wants me to examine my NI MAX. This NI MAX setupt has got a selftesting function which answers postitive. I also can create a task which is working (the device makes click sounds, which I thought would be my aim)

Might it be posible, that USB-6501 is no 'COMPACT' device and the command is only working with such 'COMPACT' devices?

Or might it be, that I'm completely on the wrong way? I thought i can add a channel and after i did that my device would give out the digital signals i want?

Thank you in advance!