On 12/31/18 3:39 PM, John Harris wrote:
On Monday, December 31, 2018 3:20:22 PM EST Wells, Roger K. wrote:
I hope this is the right list,if not please advise.

In my work I have been using and writing code to use rs232 serial ports
going back to before the first IBM PC.
Currently I primarily use USB to serial adapters, made by Prolific
(PL2303) and Belkin(F5U109/F5U409).
These devices are anything but new going back more than ten years at
least in the Belkin case and I have been using them about that long.
I have always been impressed how Linux & specifically Fedora/RedHat
recognize these devices with no fuss or fanfare.
I have just come across an anomaly that to me indicates a change in the
F29 release that I hope someone will find interesting.
Recently I needed to run a series of tests to verify data exchange at
various baud rates.
The tests have been performed on Fedora 29: (4.19.10-300.fc29.x86_64)
and CentOS 7.6: (3.10.0-957.1.3.el7.x86_64) systems.
The tests involved sending data from one system to the other and then
reversing the role of each system.
On both systems the Prolific device supported baud rates:
200,300,600,1200,1800,2400,4800,9600,19200,38400,57600 & 115200
On the CentOS 7.6 system the Belkin device supported baud rates:
300,600,1200,2400,4800,9600,19200,38400,57600 & 115200
On the Fedora  29  system the Belkin device only supported baud rates:
4800 & 9600
This was the surprise.  As long as I have been using these devices on
Fedora I am comfortable stating that I would have noticed this
limitation long ago.
Also, I am currently using three of the Belkin devices and they all have
the same performance so I don't think device failure is the cause.
If anyone would like me to run any additional tests please let me know.
I would ensure that the remote end was using the same baud rate, this is a 
common issue. Do you use `screen` or another tool?

It is all software that I/we have written here in support of sea floor mapping and search & recovery operations at sea.
I know how easy it is to make mistakes like you propose and I can assure that is not the case here.
thanks for taking the time to comment

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