Re: [Discuss-gnuradio] Change frequency USRP sink/source block on the run

Thank you for the answer, I found the command is freq. I think I will need to develop a trigger block, so that if it sees a change-frequency message, it will trigger a command to USRP sink/source. 

On Wed, Nov 9, 2016 at 1:55 PM, Osama Riad <oriad.dlecs@gmail.com> wrote:

I think you should use stream tags.In uhd you can send a command with each Burst this command is to be executed by the usrp one command is called tx_freq I think.

You can check this through the internet.

Br,

Osama

On Wednesday, November 9, 2016, Dat Luu <dat_luu@nevada.unr.edu> wrote:

Hello everyone,

I have been working on tx/rx data using USRP B210. I am able to transmit a message and verify the correct content on the receiver side. The next step I want to do is: 

1. upon sending a specific message (frequency change), I want to change the frequency of the USRP sink (tx side) 

2. upon receiving a specific message (frequency change) I want to change the frequency of the USRP source (rx side)

My question is what will be the best way to do it? I know that I will need to pause the flow graph on tx/rx side, and reload the USRP blocks with the new frequency. But, I dont know when the message will arrive; I cannot do a timing triggering on the flow graph.

Thank you in advance.