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

[Don Wilhelm]

Bill,

Just out of curiosity, I tried it here too.  Your momentary action may 
be 'normal'
I tried it in CW mode and set the K3 menu to key on DTR.
When I issued the command mode com1 dtr=on, the K3 keyed for a very 
brief time and then went back to receive - it did not stay key-down as I 
expected.

It may be that your Dell has the on and off states of the control lines 
backwards for the default (inactive) state.  I would suggest trying 
another computer to verify.

73,
Don W3FPR

Bill W5WVO wrote:
> 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
>> * KComm - http://www.g4ilo.com/kcomm.html
>> * KTune - http://www.g4ilo.com/ktune.html 
>>     
>