Usrp_server code

GNU Radio
1

Hi,

I am looking at the usrp_server code in the trunk and have the following
question.

Is there any difference between a tx/rx “port” and a “channel”?
I see that the usrp_server is always initialized with N_PORTS=4 tx and
N_PORTS=4 rx ports (total of 8 + one control port), but later on, we
only work with d_nrx_chan = d_ntx_chan = 2 tx and rx channels.

My understanding was that ports/channels are in one-to-one
correspondence. So I thought that N_PORTS is the “maximum” number of
ports/channels that the server can handle.
In that case, I would expect that
the parameters d_nrx_chan, d_ntx_chan are given to the constructor and
used accordingly…
The picture is more obscure considering that there is also a
D_MAX_CHANNELS = 16 in the usrp_server.h file…

What am I missing?

Thanks
Achilleas

2

On Fri, Nov 07, 2008 at 01:53:11PM -0500, Achilleas A.
wrote:

My understanding was that ports/channels are in one-to-one
Thanks
Achilleas

The actual number of channels available depends on the fpga image
loaded. I’m not sure how Geoerge is handling that, or whether he
provides a method to query it.

Eric