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Re: [rtl] IP useage from rtlinux on the Scanning Radar Altimeter
> >> I understand that the rtlinx system runs the LINUX "OS" portion as
> >> a low priority task under the rtlinux kernel. Does this include
> >> the IP support (UDP in particular)? Has anyone ported IP support
> >> to the rtlinux kernel level?
I'm running rtlinux on one machine ( 200mhz P5 ) which is the data system
for a radar processing 256 point waveforms every 700 us or so, and all the
display is done on a second system ( laptop running Linux ). I'm using
the laptop as an X-terminal with the "X -indirect sys-name " command.
Although my system displays are mostly written in TK/tcl, the real hog for
CPU time is the X server itself. Moving the Xserver to the laptop greatly
relived the datasystem load and works very nicely over the (local)
network. The network is only 10baseT, though the interfaces are optionally
100baseT. The laptop was purchased from Promox and is loaded with RH5.0
linux straight off the CD.
The system captures, via an interrupt, 64 256 point waveforms in a burst
10 times per second. The interrupts occur as closely as 700us apart in
the middle of the scan. Each interrupt takes abt 200us to service right
now and the last pulse in the train kicks off a rtlinux task which
processes all 64 echos. THa task takes as little as 500us to complete and
as much as 2ms depending on the angle of bank the plane is in. The
waveforms are captured by a PCI waveform digitizer and
the interrupts are generated by a custom board I built using several PIC
micro-controllers.
I'll try to get a web page together for it soon. We had our first flight
with it last week, and another one very early this morning ( 2am ).
Rtlinux is working **exceedingly well** for us. Thanks to all involved in
the rtlinux project and this email list!!!!
Kind regards,
C. W. Wright
wright@osb.wff.nasa.gov
wright@web-span.com
--- [rtl] ---
For more information on Real-Time Linux see:
http://www.rtlinux.org/