Discarded samples when sampling >2Mhz with SDK

[Tood]

Hi,

I am sampling DIO 7 from wavegen GUI. The mode is record without triggers. Sampling rate is 4MHz.
I am using 16x16k buffers. The results are perfect. No corrupt samples (see picture below).

When I am using sample code digitalin_record.cpp as base and sampling above 2MHz the result is a lot of corrupt samples.
See attached C file digitalin_record.c.

My OS is win10 and the compiler is gcc. Output from digitalin_record.exe:

$ ./digitalin_record.exe
Open automatically the first available device
Starting record...
receivedSamples: 93743 discardedCorruptSamples: 83844
sample:0  pinstate:0x01b9
sample:1  pinstate:0x01b9
sample:2  pinstate:0x01b9
sample:3  pinstate:0x01b9
sample:4  pinstate:0x01b9
sample:5  pinstate:0x01b9
sample:6  pinstate:0x01b9
sample:7  pinstate:0x01b9
sample:8  pinstate:0x01b9
sample:9  pinstate:0x01b9
sample:10  pinstate:0x01b9

What is wrong with my implementation?

Best Regards,
Tood

 

digitalin_record.c

[attila]

Hi @Tood

Use data compression by specify the interested DIOs, like for DIO 7 only:
FDwfDigitalInSampleSensibleSet(hdwf, 1<<7)

See DigitalIn_Record_Compress.py

 

You can also set the FDwfDigitalInTriggerPrefillSet 0 to start streaming data only after trigger and specify samples after trigger with FDwfDigitalInTriggerPositionSet.

[Tood]

Hi,

FDwfDigitalInSampleSensibleSet did the trick! The behavior thru SDK now matches the GUI behavior.

Thank you for your fast response!
//Tood