On Sat, 2009-01-31 at 09:03 -0500, Ed wrote:
> CSM(r) Gary Huber wrote:
> > Note; if you choose to use only DB-9 pins 2,3, and 5 for signal, you must
> > use 9600 baud and below speeds with software flow (XON - XOFF) flow control.
> >
>
>
> Thats strange, I only use 2-3-5 and 19200 and all works perfectly. I
> must have missed the above somewhere.
>
> Ed W3NR
Ordinary communications software is much happier if on the 25 pin
computer end that pin 4 is connected to 5 (RTS/CTS hardware handshake),
and pin 6 is connected to 8 to 20 (Data Terminal Ready hooked to Data
Set Ready and Data Carrier Detect). And on a 9 pin I see RTS/CTS
requires jumping pins 7 and 8. DCD to DSR and DTR needs pins 1, 4, and 6
connected. XP and VISTA may not allow serial communications without
those jumpers because they resist software connecting direct to the
hardware. Their port drivers are set only for a real modem. Ham control
software may ignore those bits, but only when it can get directly to the
hardware when the OS allows that. Standard communications software uses
those lines to determine if there is a truly a modem on the wire and if
its connected, or needs to be told to connect before data can be moved.
Then I've read on this forum that OMNI V or VI had a problem with
whether they were connected as a Data Set or a Data Terminal. If a Data
Set the cable is straight, if Data Terminal the cable signal wires have
to be crossed, e.g. null modem cable. I've also read that one of these
OMNI is easily corrected to Data Set connections by inverting an
internal connector.
Two Data Terminals (computer is always connected as a Data Terminal)
connected with a straight cable will NOT communicate.
73, Jerry, K0CQ
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|