Create Multiple Radios

Multiple Radio Blocks

When you have more than one RTL-SDR radio attached to your computer, you can simply add an RTL-SDR Receiver block for each radio. Each time you add an additional block, open the block mask and change the Radio address parameter to the USB port address of the associated radio. Click Apply to update the Hardware Information panel. For example:

If you have not yet configured your computer for multiple radios, see Configure Multiple RTL-SDR Radios.

Multiple Radio System Objects

When you have more than one RTL-SDR radio attached to your computer, you can simply add an RTL-SDR receiver System object™ for each radio. Each time you create an additional System object, call the constructor with the RadioAddress property assigned to the value of the USB port address of the associated radio. For example:

 j=comm.SDRRTLReceiver('RadioAddress','1')

j = 

  System: comm.SDRRTLReceiver

  Properties:
           RadioAddress: '1'      
        CenterFrequency: 102500000
         EnableTunerAGC: true     
             SampleRate: 250000   
         OutputDataType: 'int16'  
        SamplesPerFrame: 1024     
    FrequencyCorrection: 0        

If you have not yet configured your computer for multiple radios, see Configure Multiple RTL-SDR Radios.

Assignment of USB Ports

USB Port Address Assignment

The assignment of USB port addresses is not intuitive. If a device is plugged into the first USB port, it is always at address 0. However, if a device is plugged into any port after the first one, the address varies depending on whether a device is plugged into any of the previous ports.

This diagram shows how the USB port addresses are assigned when devices are added and then removed in first in, first out (FIFO) order.

The following diagram shows how the USB port addresses are assigned when devices are added and then removed from port 0. Note that the radio address for the second RTL device changes based on whether the first port has a device in it. To access a radio with the correct radio address, you must keep track of the plugged-in devices in order.