Hi there!

I'm having a little problem I was wondering about. I've got a 6036e DAQ-card and I'm trying to run a sine through both outputs simultaneously. My problem is that when I'am using only one output the signal's just fine but when I configure to used both outputs I "lose" every second period. I've got the same signal levels but a sine only every second period. I'm using the traditional DAQ vi's for building the program. Tried to look at the Simul AIAO Buffer.vi in example finder but didn't get much wiser. I've probably just missed something small but since I'm new to the game I'm having trouble spotting what!
/Raz

Please post a code snippet of what you've already tried

No problems!
I'm not just looking for a solution to the problem as much as just trying to understand and learn about the different functions.
cheers!

Crikey! The first thing you want to do is try again using DAQmx! You have a lot more control over DAQ processes using DAQmx, as well as more hardware functionality as well...

I aware of this but it's supposed to be implemented into already existing code which has been around for a while and I've tried the mx VI's but they don't compute to well with the older stuff... The only solution I've come to so far is to run one output channel at the time... I appreciate your help and pointer though.
Thanks mate!

No worries cobber!

Hi Raz,

I noticed a few things about your code, first of all, the 'allow regeneration' bit is not set in the Write AO buffer (First call)?
Is this intentional ?

I quickly wrote a VI where DAQ input and DAQ output on two channels is done,
but please note, that in this example there is no synchronisation between input and output !

If that is what you are looking for, you have to look further.

This example worked here on my PC. Although not with a 6036e, but a 6110PCI board.

Hope it can help You find the right solution.

Success,
Tom

Since it's supposed to be true as default I didn't bother to create a constant for it and just assumed it would work (bad idea perhaps?!). I'm just about to call it the day but I'll have look at your code first thing tomorrow morning...
Thanks a lot for Your tips and for the code. Really appreciate it!

Hi Tom!
I tried Your idea this morning, not bothring about synchronisation between in- and output... I experienced the same behaviour as before. I'll try some different setup but I'll probably end up running one output at the time. That way I know it works perfect. As I said before, I really appreciate Your help and efforts. This is still the best way of learning for me, some good ol' trial and error!
Thanks Tom!
/Raz

Here's another question maybe someone can answer!

I'm injecting a sine on one of the DAQ-outputs (got a 6036e) and configure 4 inputs for different readings of the sine through different lines (i.e. sound channels). I'm just wondering why I get a subdued signal (noise?) on the other channels when I've just connected one of the four channels. It's not a crucial thing for my readings, just wondering if someone's got an explanation.
/Raz

Hi Raz:

Try shorting the unused inputs. Very high input impedance on the inputs, a little bit of capacitive coupling between the different channels in the multiplexor, and bingo, your signal shows up as noise on the unused channels.

Even if it doesn't cause any problems, a good idea to short the unused channels.

best luck, Louis

Its been a while since I played with DAQ but as far as I can remember, even though you have 2 AO channels they are not 'independent'. You can't run each one with different frequencies, since the DAQ card has only one FIFO.

I think you are seeing this when trying to output both chans. You can set both to use the same frequency, and then they might work. See:

Can I Individually Control Each Analog Output Channel on my E-Series Board?

I have found the DAQmx performance to be much better with the 6036 and multiple AO's, since the driver is multi-threaded, it can switch between DAQ tasks without 'freezing' in-between.

Cheers,

Neville.