AbbyM

OK thank you! Now I just need to get some SMA connectors to attach to the Zmod board.

Hello, I am starting to play with a USB104 that has a Zmod 1410 ADC daughter board. I do have a Analog Discovery Pro ADP3450, but I do not have an AD 2 which the demo on the getting started page has for USB104. Are there any good ways to get started not having specifically the Analog Discovery 2? https://digilent.com/reference/programmable-logic/usb104a7/zmodadc Thanks, Abby

OK thanks. I don't see anything in the datasheet about what type it is. Is it a SAR?

OK great thanks! I guess it is specifically the -125? Since it can reach 125 MSPS?

Hello, What type of ADC does the ADP3450 use? SAR, delta sigma, or another type? I couldn't find it on the spec sheet. Thanks! Abby

Hi @attila Tried disabling network for standard boot but that did not prevent this issue. I noticed after rebooting the Raspberry Pi that it connected on the first try. It might be some kind of process being held up in the OS?

OK I will try that after the holidays, thanks!

Hi @attila I am not sure, it just occasionally loses connection on its own. Possibly power issues, we are looking into it now. But I also saw this issue on one device even using the included AC wall adapter, and if I rebooted both the ADpro and my Raspberry Pi device, the issue went away. I don't think I was letting the computer go to sleep. That command is great to know though thanks

Hi there, Is there a way to reboot the ADP3450 or ADP3250 device via the ADept runtime library? I'm using a C++ program to collect data from it but want to see if I can have the program attempt to reconnect to the ADPro if it loses connection. But during my testing, I have noticed I need to reboot the ADPro device completely to be able to reconnect once the connection is lost. Is there a way to hard reboot the device using a software command? Or does that have to be done physically through the power switch? Thank you, Abby

Thank you @reddish and @zygot This is all very helpful still as FYI for me. I had wondered if the RPi 4 was being slow at moving data over the Ethernet port. But after testing on Win10 and Ubuntu machines, I suspect there is slowness on the ADPro's ability to push data over Ethernet. @attila did you see my last post? I can't figure out how to view the recorded data files using the Config/Record option in Waveforms. I want to verify if it can do 6 MHz sampling without any errors or loss. Also I don't see the DDR buffering option that your example had. But I recall you saying something about it being native in newer versions, so am I safe to assume its already enabled?

Yes ever since I noticed Standard mode is faster than Linux mode. I also just tried testing on a Ubuntu Linux desktop , brand new powerful machine. And over Ethernet it also sees the lost samples error message even down to 1 MHz sample rate. Over USB I do not see that message at least up to 12.5 MHz

Ok thank you. I see that menu now, though my version does not include the DDR buffering checkbox, why would that be? Also I can't find where the files are recorded to on my device using this Record mode/Config button? Thanks!

OK, I think I tried to look for this option menu before but couldn't find it. Using the latest version of Waveforms. On the Raspberry Pi using 3.19.3 arm64.

Hi @attila OK, I think 128Mi samples should be plenty for 6MHz for 3CH. Is there a different way I should be recording? I tried using Waveforms GUI as well as the DWF library in C++ Or is there a special configuration or setting I am missing? Thanks

Haha I understand, on USB it seems to work as expected, but now that I'm trying it with Ethernet it boggles my mind what is going on underneath the hood. On my Win10 laptop the reported rate is still 71 MBps which checks out given the Wireshark measurements. But not for the resulting data. Hopefully someone else can respond on this thread. I really would like it to work for this project I'm using it for. It would complete the goal! Thanks

Ok, noted. I noticed also using my Win10 PC, with a direct Ethernet connection, Waveforms will lose samples even at 1-2 MHz. So maybe I'm running into a larger issue than just on the Raspberry Pi. What is even more confusing to me is that measuring traffic on Wireshark shows high data rates ~50-125 MBps being passed over Ethernet. How does it then lose samples even as low as 1 MHz? 1 MSPS of 3CH of 16-bit signed data: 5 MSPS of 3CH of 16-bit signed data: 12.5 MSPS of 3CH of 16-bit signed data: 25 MSPS of 3CH of 16-bit signed data: 100 MSPS of 3CH of 16-bit signed data:

OK, I installed Wireshark on the Raspberry Pi and definitely saw that it is only using TCP during data recording. I wonder why it is so slow then, and I had to slow the sample rate down to 100-200 kHz just so it was not losing any samples during recording. And attempting to sample faster resulted in an early stop because it would only acquire a fraction of its goal before the set time is up. This was all using the Waveforms GUI. Using both Linux mode and standard mode did not change it much. I also tried disabling Wifi completely and that only helped a bit.

Ok thank you! I installed iperf on Linux mode, and ran both TCP and UDP tests. The ADPro is the "server." It looks like ~85 MBps for TCP, and 1 MBps for UDP. What I still don't know is what is being used to transfer data during a data collection, TCP or UDP? Seems TCP is what I need to achieve the sample rates I want. (>= 6 MSPS for 3 CH)

no, I assumed the ADPro would have one automatically, is that right? I just kicked off my C++ program from the Raspberry Pi, then ran iperf from another command prompt

Hi reddish, I used this command for UDP: iperf -c 10.1.10.9 -u -i 1 -f M And this command for TCP: iperf -c 10.1.10.9 -i 1 -f M I am using a direct Ethernet connection without any DNS or other routing.

Hello, I have been looking into using Ethernet with my ADP3450 and Raspberry Pi 4, and am curious what Ethernet layers the ADPro uses in its communications? When I ran the iperf utility on the Pi, only a UDP command returned any results, and it reported a rate of ~0.125 MBps. I did not see any activity over TCP. Thanks, Abby

In reply to zygot's last paragraph, that's exactly right, though at first I didn't realize it. From all the input so far, it seems the core issue is in my Raspberry Pi 4 and its Ethernet setup, or drivers, or something. The ADP3450 seems quite capable and when I connected it to a Windows 10 laptop via Ethernet, it was getting 71 MBps. I will keep researching for any tweaks that need to be made or if anyone else has had slow performance with that setup of RPi 4 <--> ADP3450 via Ethernet. Thanks to everyones generous help so far!

I'm using a Raspberry Pi 4 Model B. With the latest 64-bit version of the OS, Debian 11. Referring to when you got 70 MBps, and the spec'd rate for Ethernet is 71 MBps. You can view it in the Waveforms application. Thanks,

@reddish What type of Linux host did you use specifically? Glad you were getting the full spec'd rate for 3 channels. Thanks for running that test!

OK, thanks! I tried to look for that DDRam buffering option but couldn't find it anywhere?