USRP2 siggen error


#1

Hello,

I am using the USRP2 with an RFX2400 daughterboard in Ubuntu Hardy
8.04.1, installation went fine (used rev 9913 plus the ready made
firmware images in http://gnuradio.org/releases/usrp2-bin/trunk) and
usrp2_fft.py works perfectly.

However, I experience the following problem when invoking
usrp2_siggen.py:

root@laforge:/home/nol/gnuradio_V_9913/gr-utils/src/python# python
usrp2_siggen.py -f 2.4G -w 200k
ethernet:write_packetv: send: Message too long
usrp2_sink_32fc: tx_32fc failed

I would appreciate some help
Thanks

Natalia Olano


#2

On Mon, Nov 03, 2008 at 11:51:09AM +0100, Natalia Olano wrote:

usrp2_siggen.py -f 2.4G -w 200k
ethernet:write_packetv: send: Message too long
usrp2_sink_32fc: tx_32fc failed

I would appreciate some help
Thanks

Natalia Olano

Thanks for pointing out the problem. I haven’t seen this one before.

Can you run this command and post the output?

$ /sbin/ifconfig eth0

Thanks,
Eric


#3

On Mon, Nov 03, 2008 at 04:19:39PM +0100, Natalia Olano wrote:

      collisions:0 txqueuelen:1000
      RX bytes:3178136520 (2.9 GB)  TX bytes:3379674 (3.2 MB)
      Base address:0x1840 Memory:fe200000-fe220000

Interesting. You’ve got an MTU of 1400 instead of 1500.

Do you have any idea of why that might be?

In any event, I’ll fix the code so that we check the actual MTU.
This might take a couple of days, given everything else on my plate.

Eric


#4

Here is the output, thanks for taking some time in this.
Natalia

root@laforge:/home/nol/mobnets/testbed# /sbin/ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:1e:37:1e:ee:4a
inet addr:134.130.222.127 Bcast:134.130.222.255
Mask:255.255.255.0
inet6 addr: fe80::21e:37ff:fe1e:ee4a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1400 Metric:1
RX packets:16302010 errors:3 dropped:19 overruns:0 frame:2
TX packets:21446 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:3178136520 (2.9 GB) TX bytes:3379674 (3.2 MB)
Base address:0x1840 Memory:fe200000-fe220000

2008/11/3 Eric B. removed_email_address@domain.invalid:


#5

Looks like your MTU is set a bit too small. Try increasing it to 1500
or maybe a bit higher and see what happens.

/sbin/ifconfig eth0 mtu 1500

Tim


Timothy R. Newman
DNI Post Doctoral Fellow
Wireless @ Virginia Tech
447 Durham Hall
Blacksburg, VA 24061
Phone: 540-231-2041


#6

Yes! The problem was the MTU and decreasing it to sharp 1500 worked. I
also updated the firmware image to the one of 3 nov because I could
not see any signal, as in
http://lists.gnu.org/archive/html/discuss-gnuradio/2008-11/msg00037.html.

Thanks for the good advice!
Natalia

2008/11/3 Newman, Timothy removed_email_address@domain.invalid: