Hello all.
This is a question that I should be able to answer, but the old grey cells aren't working. My Google-Fu must not be up to snuff, either.
I have a MOXA IP-RS232 converter that I'm going to be using over an RF WAN and I need to confirm the actual data rate that I'll be able to achieve. I have the drivers loaded (/dev/ttyr00) and a loopback plug on the end of the device. I am able to confirm that it works fine with minicom, but I'd like to be able to have a program read/write the device with a largish file and give me a throughput rating.
Short of writing my own program, can anyone point me to a good tool for that purpose. yum search RS232 and yum search serial haven't provided what I'm looking for and I can't imagine that this isn't already done.
Thanks!
Barry
On Tue, Sep 01, 2009 at 03:38:23PM -0400, Barry L. Kline wrote:
the end of the device. I am able to confirm that it works fine with minicom, but I'd like to be able to have a program read/write the device with a largish file and give me a throughput rating.
Since you have loopback adapter connected you need to read/write from the device at the same time. So... first attempt: cat </dev/ttyr00 > /dev/null & time cat large_file > /dev/ttyr00
Been a long time since I played with serial comms, but that'd be my first attempt.
Second attempt would be to make a full serial connection to another machine (port on the same machine?) and use "ckermit" to transfer a file.
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Stephen Harris wrote:
Since you have loopback adapter connected you need to read/write from the device at the same time. So... first attempt: cat </dev/ttyr00 > /dev/null & time cat large_file > /dev/ttyr00
Been a long time since I played with serial comms, but that'd be my first attempt.
Second attempt would be to make a full serial connection to another machine (port on the same machine?) and use "ckermit" to transfer a file.
Thanks Stephen.
Your first attempt was what I was trying to accomplish. The second attempt may be what I next try.
Barry
Stephen Harris wrote:
On Tue, Sep 01, 2009 at 03:38:23PM -0400, Barry L. Kline wrote:
the end of the device. I am able to confirm that it works fine with minicom, but I'd like to be able to have a program read/write the device with a largish file and give me a throughput rating.
Since you have loopback adapter connected you need to read/write from the device at the same time. So... first attempt: cat </dev/ttyr00 > /dev/null & time cat large_file > /dev/ttyr00
I'd replace /dev/null with large_file_copy, then run md5sum on both to confirm things are working reliably.
On Tue, Sep 01, 2009 at 01:33:44PM -0700, John R Pierce wrote:
Stephen Harris wrote:
cat </dev/ttyr00 > /dev/null & time cat large_file > /dev/ttyr00
I'd replace /dev/null with large_file_copy, then run md5sum on both to confirm things are working reliably.
That's the second step :-)
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John R Pierce wrote:
I'd replace /dev/null with large_file_copy, then run md5sum on both to confirm things are working reliably.
John
Nice tweak!
Thanks -- I'll make that change.
Barry
On Tue, 1 Sep 2009, Barry L. Kline wrote:
Short of writing my own program, can anyone point me to a good tool for that purpose. yum search RS232 and yum search serial haven't provided what I'm looking for and I can't imagine that this isn't already done.
Are the Kansas City cassette tape storage PLL sampling routines still about? Or hit ^h repeatedly, until sync is achieved, as we did in the old modem days .... 110 bps v 300 on a good link with a Don Lancaster Pennywhistle modem ;)
As I understand the problem it may be that the signal could degrade from whatever max data rate the circuit is rated for. I am not aware of a resampling routine in any recent kit that CentOS ships
-- Russ herrold
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R P Herrold wrote:
As I understand the problem it may be that the signal could degrade from whatever max data rate the circuit is rated for. I am not aware of a resampling routine in any recent kit that CentOS ships
Hi Russ.
This RF-WAN is a 450 MHz data radio that alleges to get 12.5KBps. They are connected such that the most appropriate allegory would be a number of TCP/IP hosts connected to a hub (not a switch).
What I need to verify is the kind of throughput I'm actually seeing and Stephen's solution may give me what I want. I know how much data is going to be crossing this, I just need to find out what kind of time its going to take.
Thanks!
Barry
Barry L. Kline wrote:
Short of writing my own program, can anyone point me to a good tool for that purpose. yum search RS232 and yum search serial haven't provided what I'm looking for and I can't imagine that this isn't already done.
For writing have you tried dd ?
nate
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nate wrote:
Barry L. Kline wrote:
Short of writing my own program, can anyone point me to a good tool for that purpose. yum search RS232 and yum search serial haven't provided what I'm looking for and I can't imagine that this isn't already done.
For writing have you tried dd ?
I used dd to create the file I'm sending, so that every test is starting with the same data and length.
Thanks!
Barry
Barry L. Kline wrote:
I used dd to create the file I'm sending, so that every test is starting with the same data and length.
How about writing it directly to the device?
dd if=source of=/dev/ttyr00 (if that's the device? I forgot)
similar to using cat though if it matters you could play with things like block size. Use time to time it, some new versions of dd include progress meters and performance info I believe.
nate
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Barry L. Kline -
John R Pierce -
nate -
R P Herrold -
Stephen Harris