diff options
Diffstat (limited to 'host/docs')
| -rw-r--r-- | host/docs/usrp_n3xx.dox | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/host/docs/usrp_n3xx.dox b/host/docs/usrp_n3xx.dox index 417b79466..ff471e46f 100644 --- a/host/docs/usrp_n3xx.dox +++ b/host/docs/usrp_n3xx.dox @@ -567,13 +567,15 @@ Using an internal reference is the default. \subsection n3xx_synchronization_external External references In order to synchronize multiple USRPs, an external reference, such as the -CDA-2990, is required. If only a clock reference is available, it is possible -to derive an internal PPS signal from the reference (which will allow devices -to share a frequency, but not a time reference). If both an external clock and -time source are provided, devices will be synchronized in frequency and time. +CDA-2990 (OctoClock), is required. If only a clock reference is available, it is +possible to derive an internal PPS signal from the reference (which will allow +devices to share a frequency, but not a time reference). If both an external +clock and time source are provided, devices will be synchronized in frequency +and time. ```cpp -auto usrp = uhd::usrp::multi_usrp::make("type=n3xx,clock_source=external,time_source=external"); +auto usrp = uhd::usrp::multi_usrp::make( + "type=n3xx,clock_source=external,time_source=external"); ``` \subsection n3xx_synchronization_whiterabbit White Rabbit @@ -584,7 +586,7 @@ configured as a White Rabbit slave. To use White Rabbit, it is necessary to provide an appropriate reference via Ethernet. This reference must be connected to SFP0. Finally, a White Rabbit-compatible -FPGA must be loaded. SFP0 will not be available for data transport in this mode. +FPGA must be loaded. SFP0 will *not be available for data transport* in this mode. The White Rabbit image is provided as a default image. To obtain the default images, simply run: @@ -593,13 +595,24 @@ images, simply run: Then, you can install the WX (or WA) image using `uhd_image_loader`: - $ uhd_image_loader --args type=n3xx,addr=ni-n3xx-<DEVICE_SERIAL> --fpga-path=”<UHD_INSTALL_DIRECTORY>/share/uhd/images/usrp_n310_fpga_WX.bit + $ uhd_image_loader \ + --args type=n3xx,addr=ni-n3xx-<DEVICE_SERIAL>,WX Once the image is loaded, select `internal` as the clock source and -`sfp0` as the time source: +`sfp0` as the time source (note: this will fail if the WX or WA image is not +currently loaded): ```cpp -auto usrp = uhd::usrp::multi_usrp::make("type=n3xx,clock_source=internal,time_source=sfp0"); +auto usrp = uhd::usrp::multi_usrp::make( + "type=n3xx,clock_source=internal,time_source=sfp0"); +// Or if you want to change it to White Rabbit after initialization: +usrp->set_sync_source(device_addr_t("clock_source=internal,time_source=sfp0")); +// Using the older time/clock source APIs is also possible: +usrp->set_time_source("sfp0"); +usrp->set_clock_source("internal"); +// The 2nd call can technically be skipped because the device implementations +// will coerce, but for consistency with other code and for being explicit this +// is the preferred way. The 2nd call will immediately return in this case. ``` For more information, refer to the [White Rabbit Homepage](https://www.ohwr.org/projects/white-rabbit), |