two tx channels start times

[Makmerfy]

Hello everyone! 

I'm trying to implement transmitter with two channels on different frequencies. I have 2942R.  10MS/s sample rate on each chanel. I need to start generation at the same time by the trigger on the pps in. I've tried to use sample project for multiple usrps for one usrp. But actualy the difference from TX0 to TX1 is about 20-60 ms.   

How can i synchronize start of generation of two channels on one USRP? 

thx.

[Jupiter02]

Hi Makmerfy,

Have you tried using the niUSRP EX Tx Multiple Outputs (Single Device, Multi Channel).vi example? This should be located in the <LabVIEW version>\examples\instr\niUSRP folder.

[Makmerfy]

No,it is not right for me I have two iq arrays of different length and continues generation.

[Jupiter02]

Hi Makmerfy,

This would still be a good starting point as you can modify the example for continuous generation. Regarding the IQ arrays of different length, you can modify the two array inputs to the Build Array function and it will automatically add zero-padding to the shorter array. If this does not suit your application, an option would be to repeat the samples of each array until they are of matched length.  

Hope this helps!

[Makmerfy]

Jupiter02,samples does not repeat,if I have some zero padding then receiver loose signal phase detection. I'm using Usrp rio API. Thx for your comment anyway.