[aprssig] KPC-3+ KISS mode delayed packet issue?

Pete Loveall AE5PL Lists hamlists at ametx.com
Fri Dec 19 16:17:47 CST 2008

Yes, there is an issue with the KPC-3/3+ firmware in KISS mode.  No, it is not a missed frame END character.  The KPC 3s seem to become confused if there is both transmit and receive activity going on at the serial port (common when being used with digipeater software).  This can only be recovered by resetting the KPC 3/3+.  In all cases that this has been seen with KPC 3s (includes 3 pluses), replacing them with other model TNCs (including other model KPCs) has completely fixed the issue.  This problem has been seen with multiple brands of software running against the KPC-3/3+ in KISS mode (including non-APRS software).


Pete Loveall AE5PL
pete at ae5pl dot net

> -----Original Message-----
> From: Curt, WE7U
> Sent: Friday, December 19, 2008 12:30 PM
> To test the missed frame END character hypothesis:  If you're
> running with Linux doing the digipeating you could perhaps tweak the
> AX.25 KISS code to send extra frame END characters in between each
> packet.  It might take months to decide whether the fix works
> though.

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