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| <== Date ==> | <== Thread ==> |
|---|
| Subject: | RE: Increasing scan rate to 10 kHz |
| From: | Emmanuel Mayssat <[email protected]> |
| To: | Evgeniy <[email protected]>, EPICS mailing list <[email protected]> |
| Date: | Tue, 26 Nov 2013 17:00:09 -0800 |
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You need hardware with proper clock and in particular a hardware circular buffer which you populate with your samples.
Software wise, you read the hardware buffer at a much lower frequency, but fast enough so it doesn't wrap around. (i.e. set the size of the hardware buffer correctly and use 2 pointers (last data written, last data read)) Read all the new data from the hardware buffer **at once** and append it to your compress record. What are you sampling and how do you currently intend to do it? can you lose chunks of data? Good luck! -- Emmanuel > Date: Tue, 26 Nov 2013 15:20:22 -0800 > From: [email protected] > To: [email protected] > Subject: Increasing scan rate to 10 kHz > > Hello, > > I can easily set scan period to 0.01 second by adding: > > choice(menuScan_01_second,".01 second") > > in dbd file. > > What about adding scan period 0.0001 second? > Similar line: > > choice(menuScan_0001_second,".0001 second") > > doesn't work. > > CLOCKS_PER_SECOND on my 8-core DELL server is 1000000 (running SL5.4). > > What should I do to set scan period to 0.0001 second? > > I need such short period to quickly fill in the circular buffer of > compress record. > > Thanks, > Evgeniy > |