From: Dave (dfisher_at_pophost.com)
Date: 2002-03-14 20:48:09
On Thu, 14 Mar 2002 13:30:48 +0000, Jim Peters wrote:
>sleeper75se wrote:
>> Testing the serial port can be done by anybody who can program and
>> owns two computers, so volunteers are welcome. Start a new thread on
>> that topic if you are interested...
>
>I took your challenge, setup a test with a Perl script dumping data at
>115200 baud down a cable with flow control disabled. There was no
>problem on my text-mode P133 laptop keeping up with this data stream
>with the machine unloaded (I was using "cat </dev/ttyS0 | tee log").
I just did some tests with my ProComp program, and I continue to get a drop of
bytes at the very beginning when I start the program (around 20 dropped
packets, less than 1 second), and then everything is fine. I am testing this
on my PIII 500Mhz notebook. I wrote two quick programs -- one which does
infinite loops with sin and cos calculations, and the other which does random
seeks in a 15mb file. I also have the ProComp on streaming data from two EEG
channels, and have four open "views" to the stream. Running the math program
doesn't bother it a bit. I did not need to increase the priority as you did,
Jim. Running the disk program, however, yields a rash of hits, losing about
140 packets! But after that initial loss, the program stabalizes and continues
running with no more data loss.
This is certainly disk controller related. I also get a lot of lost packets
when I enable my debug code which writes out a slew of stuff to the screen
inbetween getting data from the serial port, but that did not surprise me since
the writing to the screen kept it from polling the serial port.
So other than losing bytes during the initial startup of the disk program, it
seems to be fine. I'll check my DMA settings later, although they may be
disabled as they were for Jim.
Dave.
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:41 BST