[aprssig] APRS Telemetry Question
noskosteve at yahoo.com
Sat Oct 13 18:01:38 CDT 2012
--- Lynn W. Deffenbaugh (Mr) wrote that Steve Noskowicz wrote:
> > ... the Telemetry data payload packets MUST begin with "T#nn" (and perhaps "T#n") not just "T" as 101 states.
> I don't question the protocol specification, I just attempt
> to understand and implement it.
Understood and no complaints there. You've clearly taken things much further than I. I now understand what I wanted.
> If you look closely at the Telemetry Report Format on page 68 ...
In trying to understand a small part I pointed out that I did look @ Pg 68 and see that what you and Hessu reported here is not clearly specified in 101 - namely whether the # and a three digit sequence number are both required.
I take your word(s) that the # is required, but also see, due to the packets we looked at, that Hessu's code (at least) does not require 3 sequence digits.
In the end, because of the "::" Issue, I verified that the D700/D7 can't do true telem and my Q is answered and I understand a bit [no pun intended] more.
As you know I'm sure, looking @ 101 doesn't answer all questions. 101 has some rough edges.
> ... Every single character ... is part of the specification,
Not quite, as I pointed out.
> especially those highlighted in yellow.
It's obvious to me now, but I actually hadn't noticed the highlighting until you mentined it. Probably due in part that I appear to be midly yellow blind. Yellow highliter can be almost invisible for me.
Anyway, 101 says the yellow "Marks text of interest" which does not say they are manditory elements. Got a lota' years reading complex, and complete, engineering docs.
73 & thanks, Steve
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