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fedora-users: Re: Serial port permissions -

Re: Serial port permissions -

From: Bob Goodwin <bobgoodwin_at_nospam>
Date: Tue Oct 18 2011 - 17:55:47 GMT
To: users@lists.fedoraproject.org

On 18/10/11 13:30, g wrote:
> On 10/18/2011 04:42 PM, Bob Goodwin wrote:
> <>
>
>> Ok I've added "dialout" but still don't see a change in voltage,
>> on the second computer it sits at -11+? I logged out/in, perhaps
>> a reboot is required? I'll try that.
> "what we have here is failure to communicate". 8-D
>
> both, on your part and on part of computers.
>
> what you have not communicated, are you connecting to a modem, or to
> another computer?
>
> if 2 computers, they *may not communicate*. that is, *not without* a
> "null-modem" connection.
>
> for a decent understanding of rs-232 operation, see;
>
> http://www.arcelect.com/rs232.htm
>
> where you will find what you need for understanding of an rs-232 connection
> using either a db25 or db15 connector and how to make a "null-modem"
> between the 2 computers.
>
>
> hth.
>
>
> No that doesn't help! The internet is full of words on how to
> connect two computers via serial ports.
>
> I have an application that should toggle DTR and RTS and I want to
> see that at the end of an unterminated cable. I have tried to do
> that on two F-15 64 bit computers, a Dell and an HP, in both cases
> the port sits high negative ~-12 volts dc.
>
> I guess the only thin I may have that I could tie to a serial port
> would be an old dial ip modem if I can find it. I don't even have
> a wired telephone line, cell phones only in this house. But the
> modem would do for testing. Or I could cut up this serial cable
> and make a null modem cable out of it if necessary, that might be
> easier ...
>
> All suggestions welcome at this point.
>

        Brian, I assume the one connector on the back of both computers
        will be seen as ttyS0. FLDigi is set to ttyS0

        I also tried psk31lx and it does not toggle the serial outputs
        either so that makes it look like a computer configuration
        problem rather than either PSK application.

> .
>
> Bob
>
>

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