5791 Rf front end problem

[sunnykillz]

Hi 

I am using NI 5791 tranceiver equipped with PXIe-7966R FPGA.My question is that can I use this tranceiver card in full duplex mode.

That menas I can use transmit and receive channels at the same time via RF interface.I have worked on streaming example in that only one work at a time.Eiter receiver or transmitter not both works simultaneously.

I have developed a VI for tranceiver but i get error.VI and errors are attached.

[David-A]

You can receive and transmit at the same time with the 5791 FAM. The out of the box sample project demonstrates this. Once you've installed the driver you can access the project from the Getting Started Window by clicking Create Project and selecting the Simple NI-579x Streaming sample project from the list. 

[sunnykillz]

i have Run streaming example but there is no VI in host which works as both TX and RX.There arte only VI for Rx or TX not both at the same time

[sunnykillz]

Hi David

I have tried the streaming example it is only for one channerl not duplex.Kindly tell for full duplex VI

[sunnykillz]

I want full duplex working of 5791 rf tranceiver plz see VI and help

[BauerPower]

Hi!

Unfortunately I don't have a ton of time to take a look through your implementation but based on the errors you are seeing, I think you may be trying to initialize the NI 5791 two times. Initialization should only be performed once, then you will have a single while loop performing both your reads and writes. You could technically have separate while loops for Read and Write but let's keep it simple to get it working. 

I would recommend taking the Tx and Rx vi's from the sample project, and then work on merging the Tx side into the Rx example ensuring that you do not repeat configuration steps and then integrate the Tx and Rx DMA reads into the same while loop. For a simple example, you should have one configuration sequence, and then both your DMA reads and writes in the same while loop.

I've attached a vi that I used to perform a loopback in FPGA, so the Rx data was read in FPGA, then sent to the host and being transmitted. Unfortunately this vi does not perform any Host to FPGA data transfer for the Tx channel but the configuration should be similar. 

Again, I wish I had more time to help out and I hope this helps!

[sunnykillz]

Dear BauerPower,

Please tell in which library configure RX DSP vi,configure TX DSP VI,initiate Rx and Initite Tx VI etc are present.

[dnchen]

Hey there,

The VI that Rob posted was just meant to be an example of how you would need to setup the host VI. Notice that in his sample VI, the configuration for both RX and TX are done in a chain, instead of done in parallel like the VI that you posted.

Looking at the structure of that VI, I would recommend using the following order for the VIs used in the 579x host example:

1. Open FPGA Reference
2. Open Device
3. Configure Clock (scope: unwired)
4. Configure Signal (scope: rx)
5. Configure Signal (scope: tx)
6. Configure Start Trigger (scope: rx)
7. Configure Start Trigger (scope: tx)
8. Configure Stream (scope: rx)
9. Configure Stream (scope: tx)
10. Initiate Stream (scope: rx)
11. Initiate Stream (scope: tx)
12. Read/Write Data in a loop, sending triggers when appropriate
13. Abort Stream (scope: rx)
14. Abort Stream (scope: tx)

You'll need to make sure that the FPGA VI has all of the appropriate TX and RX resources that these configuration and stream VIs are calling.

[o.fujioka]

Hello, I just wanted to the same thing and made a simple VI by following Daniel's advice above.

This example host VI demonstrates how to simultaneously use both Rx and Tx on 5791. Basically, Rx only host VI and Tx only host VI are combined to do both at the same time.

Please refer to the following notes

1. Rx and Tx have same values for the following four parameters: "Frequency [Hz]", "LO Frequency [Hz]", "Reference Level [dBm]", "Sample Rate [S/s]"
2. Both Rx and Tx are set "continuous" in this example
3. Rx start trigger is configured "Tx Start Trigger" while Tx start trigger is configured "Software"
4. Rx is initiated first, then Tx is initiated. By sequentially initiating Rx and Tx, Rx does not miss the Tx Start Trigger.

Thanks!

Osamu

Japan