[Lazarus] SdpoSerial port open problems

[Bo Berglund]

On Thu, 10 Feb 2011 22:55:48 +0100, Bo Berglund
<bo.berglund at gmail.com> wrote:

>>Dont know if its any help at all, but I am also having serial port 
>>problems using USB adaptors.
>>
...
>
>Now I have problems with USB attached serial ports and lazarus
>programs using SdpoSerial as described in this thread. In this case
>the comm works fine as long as I use the *real* com port in my docking
>station. But won't work if I use one of the 4 com ports in my newly
>bought SUNIX ComHub UTS2009P4 or for that matter if I use a USB single
>channel com port adapter from ATEN. But the latter can be used if it
>is not transferred to the virtual machine where I develop the
>software.
>
>Really very confusing, and I was not planning on doing research into
>this. I was programming a comm application for data collection....

UPDATE:
Now I think I have solved the connectivity issue via the USB-Serial
converter so I can move on with the lazarus software development!

I suspected the Windows driver for the ComHub so I downloaded the
latest one from SUNIX, but that did not solve the problem. In Device
manager I let Windows 7 try to update the driver from the web, but it
told me that the driver was up-to-date at version 3.3.5.something

Then I tried googling on "prolific usb-to-rs232" which shows up in
device manager as the driver used by the ports. And I found a number
of hits that led to a website at Prolific itself (the chip
manufacturer) and there it was possible to download a driver with
version 3.3.11.152.
After installing this and rebooting the laptop it now seems like the
ports are working as intended!

So the fact that the hardware supplier does not have the latest driver
and Windows Update does not know of a later one seems not to mean that
one does not exist. In this case it is a revision step from 5 to 11 no
less and this did the trick. On Windows7X64 that is...


Bo Berglund