# Preload a signal onto USRP

**URL:** <https://www.ruby-forum.com/t/preload-a-signal-onto-usrp/221976>\
**Category:** GNU Radio\
**Created:** [August 7, 2012, 10:39pm UTC](https://www.ruby-forum.com/t/preload-a-signal-onto-usrp/221976 "2012-08-07T22:39:03Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![aris](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/258eb7/32.png) [@aris](https://www.ruby-forum.com/u/aris)\
**Post date:** [August 7, 2012, 10:39pm UTC](https://www.ruby-forum.com/t/preload-a-signal-onto-usrp/221976/1 "2012-08-07T22:39:03Z")

</div>

Hello All,  
I have a bit of a strange question. Is it possible to somehow preload a  
signal (it would be periodic) onto a USRP so that I would only have to  
send  
a signal saying “begin transmit”, and it would do so, without sending  
anything besides the “begin transmit” message over the Ethernet cable?  
I’ve  
been searching around and I haven’t found anyone who wanted to do  
something  
like this.

Thanks,  
Anisha

---

<div class="post-metadata">

**Author:** ![anisha](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/8dc957/32.png) [@anisha](https://www.ruby-forum.com/u/anisha)\
**Post date:** [August 7, 2012, 10:47pm UTC](https://www.ruby-forum.com/t/preload-a-signal-onto-usrp/221976/2 "2012-08-07T22:47:49Z")

</div>

You can preload the signal to a file. Thereafter, just use the flow  
graph:  
File source (repeat) → USRP.

Thanks,

Nazmul

On Tue, Aug 7, 2012 at 4:38 PM, Anisha G. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> * * *
> 
> Discuss-gnuradio mailing list  
> [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
> [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio)

–  
Muhammad Nazmul I.

Graduate Student  
Electrical & Computer Engineering  
Wireless Information & Networking Laboratory  
Rutgers, USA.

---

<div class="post-metadata">

**Author:** ![anisha](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/8dc957/32.png) [@anisha](https://www.ruby-forum.com/u/anisha)\
**Post date:** [August 8, 2012, 3:09pm UTC](https://www.ruby-forum.com/t/preload-a-signal-onto-usrp/221976/3 "2012-08-08T15:09:11Z")

</div>

It was for use in a multi-usrp configuration, but actually no longer  
necessary. Thank you both!

---

<div class="post-metadata">

**Author:** ![anisha](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/8dc957/32.png) [@anisha](https://www.ruby-forum.com/u/anisha)\
**Post date:** [August 7, 2012, 10:57pm UTC](https://www.ruby-forum.com/t/preload-a-signal-onto-usrp/221976/4 "2012-08-07T22:57:46Z")

</div>

If you really needed to use a USRP as a standalone signal generator you  
could probably encode the signal into a hardware block on the FPGA,  
depending on how much in the way of resources are left unused. It would  
be  
much more work than the file source method mentioned earlier. Why do you  
want it preloaded? Low latency?

-R C