"E" on USRP2 UART

GNU Radio
1

Hi,

I’m starting to see "E"s on the USRP2 UART output when my application is
running. I know that “U” means underrun but not "E"s. Anybody has an
idea ?

Thanks
Leonard

–
Lonard Marziliano, Research Engineer

Communications Research Centre Canada (CRC)
3701 Carling, Ottawa, CANADA K2H 8S2
Tel: (613) 993-0578
Fax: (613) 990-0316
http://www.crc.gc.ca

2

Actually, I have some thing like this on the terminal screen:

UEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEE
EEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEE
EEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEE
EEEEEEEUEEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEE
EEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEU
EEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEE
EEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEEUEEEEEEEEE
EEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEUEEEEEEEEEEEEEEEEEEU and
so on…

As you can see, it is very regular.

To put things in context, I’m trying to develop a DVB-S2 Modulator using
a very fast PC (six cores Xeon Dell, running Ubuntu 10.10) and the USRP2
using C++ code. I’m not using GNU Radio. So far, I’ve not been very
successful in term of getting the system running smoothly in real-time.
When I look at the signal coming out of the USRP2 , it is very choppy.
I’ve optimized a lot of code but still have the choppy issue. I’ll
looking it further but if anybody has any ideas suggestions on this,
I’ll be very happy to hear them !

Thanks,
Leonard

On 06/05/2011 11:04 AM, Leonard Marziliano wrote:

Hi,

I’m starting to see "E"s on the USRP2 UART output when my application
is running. I know that “U” means underrun but not "E"s. Anybody has
an idea ?

Thanks
Leonard

–
Leonard Marziliano, Research Engineer

Communications Research Centre Canada (CRC)
3701 Carling, Ottawa, CANADA K2H 8S2
Tel: (613) 993-0578
Fax: (613) 990-0316

3

On 05/06/2011 12:15 PM, Leonard Marziliano wrote:

so on…

Wow, its like artwork

U is underflow
E is some kind of mystery full duplex error condition

I would try out uhd, supposedly the tx flow control is a lot better:
http://code.ettus.com/redmine/ettus/projects/uhd/wiki

-Josh