Re: Streaming Serial Octave

[Stefan Mahr]

> However, initial benchmarking against PySerial streaming at 500*15
> bytes/second (with 115200 baudrate) shows some gaps in the Octave stream. I
> can detect this because one of the bytes is a counter (0-199).
>
> I am not finished with the evaluation yet and I may be able to eliminate the
> gaps..
> I write to a log file after each read that I may be able to eliminate.
> Python has a bytes in waiting function which I use in the serial read
> statement; for Octave I am using a fixed 15-byte read. Do you know of any
> way to get something like bytes_to_read = serial.inWaiting() with Octave?
> (I can try to make  a short side-by-side Python/Octave streaming script
> comparison if it would be useful.)

Instrument control doesn't support asynchronous mode yet, so it's not 
possible to get the size of input buffer.

srl_read (s0, N) reads N bytes from operating systems input buffer. This 
must happen fast enough to ensure the input buffer doesn't overflow. In 
your case I suggest to use N > 250*15.

> Second question: has anyone interfaced Instrument-Control or Octave with the
> nidaqmx API ? (analogous to PyDAQmx)That is another data source of interest
> to capture into Octave for some real time physical control applications.

No, the National Instruments API cannot be linked to octave, since it's 
not released under a GPL compatible license. If you don't distribute 
your work you are free to link directly to the API or write a simple 
wrapper.

An alternative is to use linux with comedi library [1]. Unfortunately it 
doesn't support my NI DAC, so I have no experience with this library.

Stefan

--------------------
[1] http://www.comedi.org/