HELP! General questions about OpenLogger

[CNg33]

I'm an undergraduate student who is doing research on campus and planning to utilize the offers from both OpenLogger and Analog Discovery 2, but I need to know some of the information before buying them and I have been fishing for answers for the whole week now, please help!!

Can open logger

-        Accept an input trigger to know when to start recording?

-        Is data on the SD card timestamped? If yes, how accurately?

Regarding bandwidth

-        Any way to increase bandwidth to 100 kHz?!?

-        Can somebody share signal loss vs. frequency plots of the OpenLogger? It would help a lot if Diligentinc can share theirs.

Can you provide a sensitivity plot for the OpenLogger? Our understanding is that it loses only 3dB by 50kHz. How well does it perform at 100kHz?

Can you provide the same for Analog Discovery 2

 

[attila]

Hi @CNg33

With the Analog Discover 2: the recording can be triggered and stream data over USB 2.0 to the PC from 2 scope inputs at about 1Msps. The timestamp in the device is not available only on the PC/software side. Here you can find the detailed specifications:
https://reference.digilentinc.com/reference/instrumentation/analog-discovery-2/reference-manual#scope_spectral_characteristics

I'm not familiar with OpenLogger, I'll let somebody else to reply on this.

[JColvin]

Hi @CNg33,

1) No, the OpenLogger does not support triggers to start sampling process on an analog input.

2) The OpenLogger doesn't have readable data logging to the SD card at this point in time, though I think

3) No, I do not think there is a way to increase the bandwidth on the OpenLogger since that would require a hardware change and have been informed that even if you multiplexed the ADC channels the bandwidth would not improve. The drop-off after 50 kHz will be quite sharp as it was designed similarly to the OpenScope MZ which also has a sharp roll-off after its 2MHz bandwidth at -3dB as shown on page 45 of the Microchip Masters presentation for the OpenScope MZ here. I haven't done math to figure out what the bandwidth would be at 100 kHz for an OpenLogger, though I do know it's a 2-pole filter that is used on each analog input.

Thanks,
JColvin