[drats_users] not sure on this one

[Dan Smith]

> What it really does:
>
> "Don't start transmitting again until at least X seconds have
> passed, then send the data to the radio which will not transmit
> until the frequency is clear."

Correct.

> The problem, as I now can tell, is that D-RATS can't tell if the rig
> is receiving voice traffic, only data.

Correct.

> So the best that could be done is:
>
> "Don't start transmitting again until the channel has been clear of
> any DATA traffic for X seconds."

Yeah, but is there any point in that?  I think the only point in what
is currently implemented is to leave some space between exchanges
between two machines.

> That would require the timer to continually be reset to zero
> whenever the serial port was receiving characters from the rig.
>
> The reason I was hoping for the overall timer, including voice, is
> that on a busy mixed voice/data net -- it would be nice if the data
> stations would "back off" until voice was off-air for 5 seconds.
> Then "after" the last voice transmission -- the data stations pop
> back up and continue whatever they were doing, still leaving pauses
> in-between transmissions, like the second English scenario above.
>
> But I don't see any way to accomplish that -- in the current rigs,
> right?

Correct.  The only way I can tell if the frequency is clear is to send
some data to the rig and see if it responds with XOFF after about 100
bytes of data.  Transmitting data to detect if the frequency is clear
is not particularly helpful :)

The real problem is, I think, that the repeaters introduce a 1-3
second delay between the input and the output.  This almost guarantees
that two stations on a repeater are unable to avoid stopping on each
other unless they're coordinating with each other.  A good reason why
simplex data works a heck of a lot better :)

> Perhaps if voice stations are also sending GPS data or other
> low-speed data, D-RATS could "see" those characters flying by (even
> if it's some other data application's data D-RATS can't read) and
> continue to "hold" waiting for the channel... but the typical voice
> transmission doesn't send any data at all to D-RATS, does it Dan?

Yes, I could do that.  It would work for any transmission that had a
data component.  However, you are correct that a normal voice
transmission has nothing in it unless the GPS is enabled.  It would be
nice if the radios would send the status sentences even when a GPS was
not connected or synced, much like NMEA GPSes do until they get a
lock.  That would let you simply ask people to turn on their GPS if
they're not using data.  However, I'm sure ICOM thought they were
doing everyone a favor by not flooding the channel with useless data
and I wouldn't have disagreed with them at the time :)

-- 
Dan Smith
dsmith#danplanet.com, s/#/@/
www.danplanet.com
KK7DS