How to run a basic instrument on alpha 250

[v-shetty]

Hi Team,

its a newbie issue.

i could able to setup and install all the prerequisites needed for the alpha 250 and i am able to build and run successfully.

but i have trouble in testing how the instrument running

I would like to know if i want to test the loopback and fft instrument, how i need to connect the wiring. do i have to use the RF ADC/DAC or Precission ADC/DAC and also please let me know how to i connect them.

[tvanderbruggen]

Hi,

Both instruments loopback and fft are using the RF converters.

To test the fft instrument, you can connect a RF DAC output (OUT0 for example) to a RF ADC input (IN0 for example). Adjusting the OUT0 DDS frequency on the instrument web page you should see a peak at the same frequency.

To test the loopback instrument, you can connect a signal from a waveform generator (amplitude below 1 Vpp) to IN0 and look at OUT0 on a scope. You should observe the waveform generator signal replicated on the output (see for axample the Input to output latency section on the ALPHA250 web page).

[v-shetty]

Hi Vanderbruggen,

Thank you for the response.

To test loop back, i did exactly what you suggested and i run the instrument.

[tmp/examples/alpha250/loopback//loopback.zip] OK curl -v -F loopback.zip=@tmp/examples/alpha250/loopback//loopback.zip http://192.168.1.100/api/instruments/upload

• Trying 192.168.1.100...
• TCP_NODELAY set
• Connected to 192.168.1.100 (192.168.1.100) port 80 (#0)

  POST /api/instruments/upload HTTP/1.1 Host: 192.168.1.100 User-Agent: curl/7.58.0 Accept: / Content-Length: 737503 Content-Type: multipart/form-data; boundary=------------------------17daabcbdaf300f5 Expect: 100-continue

  < HTTP/1.1 100 Continue < HTTP/1.1 200 OK < Server: nginx/1.10.3 (Ubuntu) < Date: Thu, 11 Feb 2016 16:28:45 GMT < Content-Type: text/html; charset=utf-8 < Content-Length: 33 < Connection: keep-alive <

• Connection #0 to host 192.168.1.100 left intact Instrument loopback.zip uploaded.curl http://192.168.1.100/api/instruments/run/loopback Instrument loopback.zip successfully installed

Even after successfully running, i still dont see any signal at OUT0. i give square wave signal 10Hz 0.5Vpp at IN0

Do you suggest me any debug ideas?

[tvanderbruggen]

If you go on the setting page (192.168.1.100/koheron) is the loopback instrument status set to running ?

Also 10 Hz is a very low frequency, can you use something like 1 MHz ?

[v-shetty]

I tried with 1Mhz , but still no output. in the webpage , status is Running for loopback.

Also , I tried the FFT intruments , it works totally fine, with web page i can control

[tvanderbruggen]

In the loopback design (https://github.com/Koheron/koheron-sdk/blob/master/examples/alpha250/loopback/block_design.tcl) we've commented out the 2 lines connecting ADC0 to DAC0 and ADC1 to DAC1.

Can you uncomment the 2 lines and rebuild the instrument ?

[v-shetty]

@tvanderbruggen

super , works good. i appreciate your support Thanks a lot

[v-shetty]

closing the issue as it is resolved