Re: Cannot connect tmd700a with yaac

Joseph LaFerla

HI David


Actually no, I have a real com port but I have had my share of troubles with the prolific chip.  I have two usb serial adapters to run my home automation software on my raspberry pi but otherwise have tried to steer clear of them if possible.  I still like “real” com ports.





Sent from Mail for Windows 10


From: David Head
Sent: September 24, 2020 10:56 AM
Subject: Re: [TMD700A] Cannot connect tmd700a with yaac


Since very few computers have real RS-232 ports any more, I'm assuming you're using some kind of USB to RS-232 adapter.   If so, here's an anomaly I ran into a few weeks ago.

I have such an adapter, a Trendnet TU-9S if I remember right, which has the infamous Prolific chip set that everyone rags on and says doesn't work and so forth.   So I attempt to program in TS-2000 after a full reset a few weeks ago, and in spite of the setup being exactly the same as it was previously, I couldn't communicate with the TS-2000.   I tried lots of stuff, including putting a new TU-9s into the system.   Still wouldn't work.

Then I retrieved the cable from RT-systems that came with their programming software, put it in the line, and things started working.   I was able to program the TS-2000 with all the info I had saved previously.

Why did the old Prolific-based USB to RS-232 adapter stop working?   I can only speculate that the bunches of updates that Windows is continually receiving somehow messed with the USB communications.   They keep updating Win 10, and this and that stop working or work differently, it just keeps happening.   That might be the problem.  

Dave Head

At 09:58 AM 9/23/2020, you wrote:

I am trying to connect my tmd700a with my aprs client yaac and am getting an error message that the com port cannot open.  I have a straight through rs232 cable connecting the radio to the computer as mentioned in the manual.  I have hardware flow control selected in the com port, the radio and yaac.  I have 9600 selected in both the radio and yaac.  When I try to enable the port, I get a java error saying "Unable to open serial port" .  I have tried everything I can think of to no avail.

I have even tried a null modem cable just in case but that does not work.  I am sure I must be missing something obvious.  Any thoughts would be welcome.  Thanks in advance.



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