The NI-USRP can transmit and receive signals with distinct programming flow for each.

Transmit Signals

The following diagram shows the programming flow of a transmit (Tx) application using the NI-USRP API. This diagram illustrates how to open a Tx session, configure the signal, transmit the signal, and close the Tx session.

Figure 3. Tx Programming Flow


1. niUSRP Open Tx Session—Opens a Tx session to the device.
2. niUSRP Configure Signal—Configures properties of the Tx signal and returns the actual (coerced) values from the device.
3. niUSRP Write Tx Data—Writes data to the specified channel list.
4. niUSRP Close Session—Closes the session handle to the device.

Receive Signals

The following diagram shows the programming flow of a receive (Rx) application using NI-USRP. This diagram illustrates how to open a Rx session, configure the signal, initiate acquisition, receive the data, analyze and present the data, stop the acquisition, and close the Rx session.

Figure 4. Rx Programming Flow


1. niUSRP Open Rx Session—Opens an Rx session to the device.
2. niUSRP Configure Signal—Configures properties of the Rx signal and returns the actual (coerced) values from the device.
3. niUSRP Initiate—Starts the Rx acquisition.
4. niUSRP Fetch Rx Data—Fetches data from the specified channel list.
5. Analyzes and presents data returned from the device. This example uses the Power Spectrum VI to analyze data.
6. niUSRP Abort—Stops an acquisition previously started.
7. niUSRP Close Session—Closes the session handle to the device.