Start a new topic

Noise with FMC151

Hello,


I am trying the reference design provided with ML605 and FMC 151. I am generating a 5MHz sine wave with an amplitude of 1V. I am communicating with the board with Ethernet.  I am using the following cable to connect the FMC 151 (MMCX) with a signal generator : http://www.pasternack.com/mmcx-plug-bnc-female-rg174au-cable-assembly-pe36738-48-p.aspx


The waveform obtained with noise is attached with this post. I was wondering if the board would have so much noise in the waveform. I also noticed that the board is becoming much warmer IC. Is this normal?


regards,
Paul




Hello,


I have uploaded the text files for both the tap delays in two posts.


We do not use the software provided by 4DSP much. We use the software just to make sure that the board is working as expected. We added our own hardware units to get the ADC values and do some processing. Values are also generated by our module to the DAC.


We are using a desktop fan for cooling now.  I think we are using an older version of the board as it was purchased at least 1-2 years back.  The FPGA used inside is XC6VLX240T-1FFG1156.

Paul


Also, what revision of ML605 do you have?  we tested them with rev D but there are later boards that can potentially affect timing on the lines - you'll really need to get the code and compile and change the tapiod_clk values in order to adjust the timing differences on the board.


Attached are two RAR files - tap delay 5 and tap delay 10.  Please run it in command prompt in administrator mode and let me know if it works or not.

You will need to run this file on a computer that has the BSP installed (so the appropriate DLLs are in the path).


On cooling - you must have  fan blowing on the FMC151 card or another air cooled mechanism.  If not, the board could be damage and you can definitely see problems that you're currently experiencing.  You can use a desktop fan for this if you don't have the other types.  Basically it has to be air cooled.
I would start the generator with -3 dBm power and slowly go up.  You should not see data near 32k or -32k at that point.

The harmonics that I see from your latest output shows that the signal seems to be clipped.  Also, I assume you look at the generator waveform, right?

On the software - you guys do not build the C code at all?  How do you test your own design?  I can provide the binaries but at some point you will need to build the code.

Anyway, I will send you a few RAR files of various settings shortly of the executable.



Hello,


Yes. The temperature of the board is a high. We don't have any cooling mechanism and the board do not have any cooling system either. 


It would be great if you could build the binaries after building the reference application so that I can test it. We are already occupied with the design part of the project and we are loosing too much time because of the problems in the board.


If there is a timing issue with this board, I could check everything with a spare ML605 board and see if I have any problem. When I give external signal, how do I make sure that the signal does not get clipped by the ADC?




Our deadline for deliverables are approaching and hence I would like to know if we can get a new board shipped to us. Once we get the new board,  we can ship-out the old board.This will enable us to work atleast with the channel 1 of the ADC.


Paul




The values are 16 bit aligned, so this is normal that you'll see the results up to +/- 32k.

However, the signal looks clipped (i.e. overpowered).    Usually when it's overpowered, you get that type of waveform where the harmonics are completely overpowered. 

Also, how high is the temperature on the ADC board?  I assume there is a fan or some cooling on the ADC board?  It gets really really hot and it could be damaging to the board if there is no cooling.

Can you build the reference application with Visual Studio?  Our firmware/hardware engineers suspect perhaps a timing issue on that particular board (timing adjustment might be needed). 

You can also feed an external signal in but making sure it won't over clip the ADC and see if the result change.  Please only use the reference application when you do this type of data capture.

If you can tweak the reference application, you can change this:

[b]2. If they are setup they can tweak the tapiod_clk value in main.cpp. The range is from 0 to 31[/b][b]                case CONSTELLATION_ID_FMC151_ML605:[/b][b]                                printf("Found ML605 hardware\n\n");[/b][b]                                tapiod_clk = 0x00; tapiod_data = 0x00;[/b][b]                                break;[/b]
the range for tapiod_clk is from 0 to 31.  if you can't change it perhaps I can build you binaries that has differnet values (5, 10, 15, 20) to try out. 


Tony


Hello,


I ran the same test, this time connecting to channel 1 instead of channel 2 and I get much better results. The text files are uploaded. But still, in the analyzer, I still see lots of noise.


Please suggest a solution for this problem.


When I see the adc1.txt files, I see values from -31,000 to 32,000. With a 14 bit ADC, I expect values from 0 to 16383 or from -8192 to 8191. How is it possible to interpret the values


Thank you.


regards,
Paul
Hello,

I updated by BSP to latest version (one released on last friday), but problem still persists. I have uploaded the latest set of text file after running FMC15xApp.exe.

Paul
Yes, the firmware can be changed if there were issues found and fixed/addressed.  You should enable extraction of firmware when you update the BSP and use the latest one. 

I ran the latest software (BSP release as of last Friday) on a board that is under testing in our lab and the ADC results looks good.  I think I gave you the one which was built under debug mode (sorry).  If you download the latest BSP it will have the right build.

Hi,


I replaced the FMC15xApp.exe with the new exe file that you gave me. When I run, I get the following error :


[b][i]The program can't start because of missing MSVCR110D.dll is missing from your computer. Try reinstalling the program to fix this problem. [/i][/b]


I am downloading the latest available BSP from 4DSP and I will run the FMC 15xApp available in the latest version.


I would like to know if the firmware in the RECOVERY directory would change depending on the BSP updates?


regards,
Paul

Hi Paul,

Just one more try - attached is an exe file with the later build of the BSP for the 15xAPP.  please attach the adc files again with this run.

Tony
Hi,


The 4DSP version installed on the host computer is 2.230.1 released on 9 May 2014. There is no filter connected to the loopback system.


Please note that I connected DAC0 to ADC 0. I used the 2 of the following cables to create a loop-back design.


http://www.pasternack.com/mmcx-plug-bnc-female-rg174au-cable-assembly-pe36738-48-p.aspx


Please let me know how to proceed further.


regards,
Paul

Hi paul,

It definitely looks like there is something wrong with the hw or firmware.  But just to double check, what version is your BSP?  (there should be a date on the 4FM GUI application for the version).

And just to verify, your cable is just a standard loopback cable (short, without any filters or anything in between, right?)   

I will ask one of our guys to start the process to return the board.

Tony

Thanks a lot for the reply.

I ran the application which created 4 text files.

These files are attached with the document. Please observe these values and let me know how to proceed.

Thank you.

regards,
Paul