sampling rate

[roberto]

Hi,

We have a 256 channel Digital Lynx, which we want to use for 32kHz continuous recording. We want to process all spike information off-line, therefore we will write the continuous datafiles using the full sampling rate of the system.

What is the relevance of the SCRate parameter? The documentation states:

-SCRate
This is used to set the sampling rate of ALL Spike Channels (Tetrodes, Stereotrodes and Single Electrodes).
Parameters:
SamplingRate specifies the sampling rate in Hz (usually 32000 is a good value to use).

If I set it to 25000, the CPU is busy 30% and I get many hunt errors. If I set it to 0, the CPU is only busy for 5% or even less and there are no hunt errors. Apparently the Cheetah software is doing something with this value, even though my configuration does not include spike channels.

I also noticed that changing it results in a different (reported) sampling frequency in the *.Nsc files, whereas I would expect from its description that it is unrelated to the continuous channels.

best regards,
Robert Oostenveld
F.C. Donders Centre

[bruth]

Actually the CSC sampling rate is based off of the SCRate. If you look in your CSC configuration file, you will see a -SCFreqDivisor parameter underneath the CSC Aquisition Entity creation. The value following that parameter sets the CSC sampling rate to be SCRate / SCFreqDivisor .

Edit: SCFreqDivisor commands are ignored by DigitalLynx systems. This command only works with our Analog systems.

[jerlich]

Hi Robert,
That is a ton of data!!!
What do you do with it?
Or more specifically, what kind of storage array have you set up to deal with the massive amounts of data you are collecting?
-Jeff