 |
USRP Hardware Driver and USRP Manual
Version: 003.009.004-0-g2b5a88bb
UHD and USRP Manual
|
|
|
USRP Hardware Driver and USRP Manual
Version: 003.009.004-0-g2b5a88bb
UHD and USRP Manual
|
|
In most cases, USB 3.0 bus power will be sufficient to power the device. If using USB 2.0 or an internal GPSDO, an external power supply or a cable designed to pull power from 2 USB ports (USB 3.0 dual A to micro-B or B) must be used.
UHD software will automatically select the USRP B2X0 images from the installed images package. The image selection can be overridden with the fpga and fw device address parameters.
Example device address string representations to specify non-standard images:
fpga=usrp_b200_fpga.bin -- OR -- fw=usrp_b200_fw.hex
The master clock rate feeds the RF frontends and the DSP chains. Users may select non-default clock rates to acheive integer decimations or interpolations in the DSP chains. The clock rate can be set to any value between 5 MHz and 61.44 MHz (or 30.72 MHz for dual-channel mode). Note that rates above 56 MHz are possible, but not recommended.
The user can set the master clock rate through the usrp API call uhd::usrp::multi_usrp::set_master_clock_rate(), or the clock rate can be set through the device arguments, which many applications take:
uhd_usrp_probe --args="master_clock_rate=52e6"
The property to control the master clock rate is a double value, called tick_rate.
The default clock rate setting is to automatically set a clock rate depending on the requested sampling rate. The automatic clock rate selection is disabled when either master_clock_rate is given in the device initialization arguments, or when uhd::usrp::multi_usrp::set_master_clock_rate() is called.
Note that the master clock rate must be an integer multiple of the sampling rate. If a master clock rate is chosen for which this condition does not hold, a warning will be displayed and a different sampling rate is used internally.
Nevertheless, there are multiple valid values for the master clock rate for most sampling rates. The auto clock rate selection attempts to use the largest possible clock rate as to enable as many half-band filters as possible. Expert users might have cases where a more fine-grained control over the resampling stages is required, in which case manually selecting a master clock rate might be more suitable than the automatic rate.
The property to dis- or enable the auto tick rate is a boolean value, auto_tick_rate.
The B200 features an integrated RF frontend.
The RF frontend has individually tunable receive and transmit chains. On the B200 and B200 mini, there is one transmit and one receive RF frontend. On the B210, both transmit and receive can be used in a MIMO configuration. For the MIMO case, both receive frontends share the RX LO, and both transmit frontends share the TX LO. Each LO is tunable between 50 MHz and 6 GHz.
All frontends have individual analog gain controls. The receive frontends have 73 dB of available gain; and the transmit frontends have 89.5 dB of available gain. Gain settings are application specific, but it is recommended that users consider using at least half of the available gain to get reasonable dynamic range.
The analog frontend has a seamlessly adjustable bandwidth of 200 kHz to 56 MHz.
Generally, when requesting any possible master clock rate, UHD will automatically configure the analog filters to avoid any aliasing (RX) or out-of-band emissions whilst letting through the cleanest possible signal.
If you, however, happen to have a very strong interferer within half the master clock rate of your RX LO frequency, you might want to reduce this analog bandwidth. You can do so by calling uhd::usrp::multi_usrp::set_rx_bandwidth(bw).
The property to control the analog RX bandwidth is bandwidth/value.
UHD will not allow you to set bandwidths larger than your current master clock rate.
Below is a table of the B200/B210 LED indicators and their meanings:
| Component ID | Description | Details |
|---|---|---|
| LED600 | Power Indicator | off = no power applied red = external power applied blue(red prior to rev 6) = USB power applied |
| LED800 | Channel 2 RX2 Activity | off = no power applied green = receiving |
| LED801 | Channel 2 TX/RX Activity | off = no activity green = receiving red = transmitting orange = switching between transmitting and receiving |
| LED802 | Channel 1 TX/RX Activity | off = no activity green = receiving red = transmitting orange = switching between transmitting and receiving |
| LED803 | Channel 1 RX2 Activity | off = no power applied green = receiving |
| LED100 | GPS lock indicator | off = no lock green = lock |
Below is a table of the B200mini LED indicators and their meanings:
| Component ID | Description | Details |
|---|---|---|
| PWR LED | Power Indicator | off = no power applied on = power applied (external or USB) |
| TRX LED | TX/RX Activity | off = no activity green = receiving red = transmitting orange = switching between transmitting and receiving |
| RX2 LED | RX2 Activity | off = no activity green = receiving |
| S0 LED | Reference Lock | off = no activity green = locked |
| S1 LED | Reference Present | off = reference level low or not present green = reference level high |
TX LED indicators are on when transmitting data and off when no samples are available to transmit. RX LED indicators are on when sending samples to the host and off when unable to do so. This means that TX/RX activity LED indicators will blink off in a temporary transmit underflow or receive overflow condition, indicating that the host is not sending or receiving samples fast enough. The host will be notified of the condition and output a "U" or "O" as well.
Below is a table showing the B200/B210 external connections and respective power information:
| Component ID | Description | Details |
|---|---|---|
| J601 | External Power | 6 V 3 A |
| J701 | USB Connector | USB 3.0 |
| J104 | External PPS Input | 1.8 V - 5 V |
| J101 | GPS Antenna | GPSDO will supply nominal voltage to antenna. |
| J100 | External 10 MHz Input | +15 dBm max</td |
| J800 | RF B: TX/RX | TX power +20dBm max RX power -15dBm max |
| J802 | RF B: RX2 | RX power -15dBm max |
| J803 | RF A: RX2 | RX power -15dBm max |
| J801 | RF A: TX/RX | TX power +20dBm max RX power -15dBm max |
Below is a table showing the B200mini external connections and respective power information:
| Component ID | Description | Details |
|---|---|---|
| USB3 | USB Connector | USB 3.0 |
| J1 | TRX | TX power +20dBm max RX power -15dBm max |
| J2 | RX2 | RX power -15dBm max |
| J3 | External 10MHz/PPS Reference | +15 dBm max</td |
Below is a table showing the B200/B210 on-board connectors and switches:
| Component ID | Description | Details |
|---|---|---|
| J5021 | Mictor Connector | Interface to FPGA for I/O and inspection. |
| J5031 | JTAG Header | Interface to FPGA for programming and debugging. |
| J5042 | GPIO Header | Header connected to the FPGA for GPIO purposes. |
| S700 | FX3 Hard Reset Switch | Resets the USB controller / System reset |
| U100 | GPSDO socket | Interface to GPS disciplined reference oscillator |
1 Only on the B210
2 Only since rev. 6 (green board)
Below is a table showing the B200mini on-board connectors and switches:
| Component ID | Description | Details |
|---|---|---|
| J5 | JTAG Header | Interface to FPGA for programming and debugging. |
| J61 | GPIO Header | Header connected to the FPGA for GPIO purposes. |
| SW1 | FX3 Hard Reset Switch | Resets the USB controller / System reset |
1 GPIO pinout is 1=3.3V, 2=GPIO_0, 3=GPIO_1, 4=GPIO_2, 5=GPIO_3, 6=GND, 7=3.3V, 8=GPIO_4, 9=GPIO_5, 10=,GPIO_6 11=GPIO_7, 12=GND
1.8.13