[Elecraft] Serial port RTS problem [was: Different mode]

[Bill W5WVO]

Hi Julian,

Fascinating! (as Mr Spock would say).

I first enabled PTT=RTS on the K3. The rig keyed up as usual.

I then asserted the command line you suggested in a command window, and the RTS 
line dropped but then immediately reasserted itself -- I would say the dropped 
time was maybe 200 ms.

As an aside, any application that actually had control of the serial port would 
block the user's attempt to control it through the command line. I verified this 
by running my logging program (which talks with the K3) and then trying the 
command. Windows responded that the serial port was not available. I closed the 
logging program and tried again, and it worked as described above.

I'm beginning to think this is some kind of weird-ass Dell snafu... Great! :-(

Thanks,

Bill W5WVO


Julian, G4ILO wrote:
> Bill W5WVO wrote:
>>
>> Julian et al.,
>>
>> I have always used VOX for WSJT keying, so I tried setting it up for
>> RTS control
>> as you suggest above. But when I try to configure the K3 for ether
>> PTT=RTS or
>> PTT=DTR with NO RS232-controlling application (like WSJT) running,
>> the rig keys
>> up (and switches into TEST mode automatically as per the manual). If
>> I then
>> disconnect the serial cable at the laptop serial connector, the keyed
>> condition
>> disappears.
>>
>> My conclusion is that the laptop's serial port is asserting RTS and
>> DTR full-time for some reason. It's a 2-year-old Dell Latitude D820,
>> Core2 processor, 2 GHz, 2 GB RAM, running XP Home. It has one true
>> RS232 port (COM1),
>> the one I'm using. Flow control is set to NONE, so it should not be
>> asserting
>> these lines by default. Has anyone ever encountered this?
>>
>>
>
> For many years I have used RTS for PTT and CW keying with various
> software and radios and I have never come across this. Normally if
> the rig is switched on when the computer starts up the RTS (PTT) is
> briefly toggled three times during the startup procedures but it is
> always left on the off position. It seems an unlikely thing for Dell
> to deliberately do, so I wonder if you have some program or driver
> that tries to scan the serial ports at start-up and leaves RTS / DTR
> in the wrong state afterwards.
>
> There is one program I find that leaves RTS on when it closes and very
> annoyingly it is Fldigi for Windows which I use rather a lot. But
> apart from WSJT there is WSPR and the AGWPE packet engine that all
> use simple PTT control so I really need to leave that K3 option
> enabled.
>
> While typing this I had a stroke of inspiration. If you type the
> command:
>
> mode com1 rts=off dtr=off
>
> in a command window that should turn RTS and DTR off. So if you could
> put that command into whatever the Windows XP equivalent of
> autoexec.bat is (assuming there is one) that should solve the problem.
>
> -----
> Julian, G4ILO. K2 #392  K3 #222.
> * G4ILO's Shack - http://www.g4ilo.com
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