[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] [USRP-users] minimum PPS voltage for N200

From: khalid.el-darymli
Subject: Re: [Discuss-gnuradio] [USRP-users] minimum PPS voltage for N200
Date: Tue, 3 May 2016 13:32:05 -0230

Thanks Marcus.

OK, I'm communicating with the external Firefly-1A GPSDO unit using an RS 232 cable. I am able to do so after enabling echoing on RS 232 from the GPSDO. Would that be a problem? Do I need to completely disable the RS 232 echoing, even while the RS 232 cable is completely unplugged?

When the RS 232 cable is plugged-in, N200 DETECTs it as an INTERNAL GPSDO. When I completely unplug the RS 232 cable on both ends, I am not getting any messages for detecting neither external nor internal GPSDO. It only shows the following in the terminal for both N200 devices,

(1) catch time transition at pps edge
(2) set time next pps (synchronously).


On Tue, May 3, 2016 at 12:20 PM, <address@hidden> wrote:

The PPS input is conditioned with a:


Looks to me like it should work just fine.




On 2016-05-03 10:23, khalid.el-darymli via USRP-users wrote:


I'll appreciate any help on the following. According to the link below [1], the PPS voltage for N200 should be in the range [3.3, 5] V p-p.
[1] http://files.ettus.com/manual/page_usrp2.html#usrp2_hw_leds

I am getting a PPS signal through fan-outs from an external Firefly-1A GPSDO. I measured the output PPS voltage using a scope, and it is 2.52 V p-p (terminated with 50 ohms).

Would this relatively low PPS voltage work for N200?  I am having a problem syncing two N200 units (2 LFRX/ 1 LFTX ), and I am not sure if this would be the cause?

Thank you.

Best wishes,

USRP-users mailing list

reply via email to

[Prev in Thread] Current Thread [Next in Thread]