Transferring data from buffer

[DerAstrophysiker]

Hello everyone,

we want to measure data with the Red Pitaya. One of our problems is the size of the memory buffer which I know has already been addressed by many people. In order to circumvent the problem we want to do the following: After measuring the data and filling up the buffer, we want to free the buffer and save the data to a textfile. We want this process to repeat as long as we need it to. Ideally, the buffer is only a node for streaming data to a textfile. How can we implement this? So far, we don't see a way to empty the buffer or stream the data. We use the function "rp_AcqGetOldestDataV". The first time (up until the buffer is filled for the first time), everything works just fine. After that, however, we either have no data or data that makes no sense.

Greetings

[Nils Roos]

The description of rp_AcqGetOldestDataRaw() indicates that the call reads data that was collected following the last trigger event, and should only be used once collection has finished.

Do you set up a trigger and wait for it to happen (and then wait for recording to finish) everytime before you call rp_AcqGetOldestDataRaw() ?

[DerAstrophysiker]

We do set up a trigger; after it has happened, we use the function I mentioned above. For triggering, we used the function within a while function. For the first 16.384 data points, everything works just fine, but somehow the buffer doesn't seem to empty. (The buffer is intended for exactly that: being a buffer for transferring the data to another medium, so we need it to be able to write continuously.) We cannot overwrite the data. After testing the function "rp_AcqGetWritePointAtTrig" we came to the conclusion the write pointer doesn't reset either.

We tried to use rp_AcqGetLatestDataV instead, but the problem persists. So probably it is due to the write pointer not resetting, isn't it? Apart from that, the trigger doesn't seem to reset, either.