[Xastir] Help with Acks

John Gorkos jgorkos at gmail.com
Thu Sep 27 10:06:04 EDT 2012


I'm using Xastir to test the AVRS/Locate server, and I'm having a hard time
grasping the reply-acks concept.
Here's a sample of the conversation:
AB0OO>APX201,TCPIP*,qAC,T1FIFTH::LOCATE   :N5TEX-9{0a}7
Sending ACK to AB0OO for MSG NUM 0a}7
Thu Sep 27 06:58:25 PDT 2012:  AB0OO wants to know the location of 'N5TEX-9'
Sending AVRS>APZ013,TCPIP*::AB0OO    :ack0a}7
Thu Sep 27 06:58:25 PDT 2012:  Last position of N5TEX-9 at Tue Sep 25
16:41:44 PDT 2012 at 3609.17N/09555.35Wj
lastHeard is Tue Sep 25 16:41:44 PDT 2012
LOCATE>APZ013,TCPIP*::AB0OO    :N5TEX-9 heard 1d14h16m41s ago 3.91mi E of
Tulsa, OK{8
AB0OO>APX201,TCPIP*,qAC,T1FIFTH::LOCATE   :ack8{8

Briefly:  AB0OO using Xastir sends a message to "LOCATE" with the callsign
of N5TEX-9.  The LOCATE server sees that, and acks immediately, so Xastir
stops sending the request. Then the LOCATE server looks up the last known
position for N5TEX-9, and sends a new message (with a new message number) to
AB0OO.

So, Xastir is using the reply-acks format, as described here:
www.aprs.org/aprs11/replyacks.txt
The "message number" is "0a}7" when viewed from the original paradigm.   I
attempt to send that ack to the Xastir client in the line that starts with
"Sending ACK", but for some reason , Xastir ignores it.  Am I using the
incorrect format for my ack?  Eventually (tomorrow, I hope), I'll implement
the reply-acks algo, but I need this to work for ALL clients, regardless of
whether they use the new paradigm or the old paradigm, so this testing is
important.

Any thoughts?

John Gorkos
AB0OO






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