Kantronics KPC–3 Plus User Manual page 102

Configuring Digis for HF/VHF Gateway Operations
This example assumes the use of at least one multi-port TNC that supports both HF
and VHF operation.
In this example, we demonstrate cross-band (gateway) digipeating, using selected
Kantronics' TNCs. A UI frame is launched on HF and repeated on VHF four times. A
KAM Plus and two KPC-3 Pluses (with call signs C, B, and D) are configured as
digipeaters and another KAM Plus (call sign A) is set to launch a UI frame from its HF
port. The digis are configured with an alias of FLOOD and UIDWAIT is set ON. In
addition, MYGATE for digi C (the KAM Plus) is set to C-3 and its UIGATE is set
ON/OFF; that is, it is enabled to digi from HF to VHF but not from VHF to HF. The KAM
Plus, with call sign A, is then used to initiate an unproto packet with the path GPS via C-
3, FLOOD4-4. Either KAM Plus will then display the resulting action as follows:
A>GPS,C-3,FLOOD4-4/H: <UI>:234
A>GPS,C-3*,FLOOD4-4/V: <UI>:234
A>GPS,D*,FLOOD4-3/V: <UI>:234
A>GPS,C*,FLOOD4-2/V: <UI>:234
A>GPS,B*,FLOOD4-3/V: <UI>:234
Station C hears the HF unproto packet of station A and digipeats it via its GATEWAY
out its VHF port. Digis B and D hear the VHF UI packet and store it for digipeating, and
D transmits first. In turn station C hears station D's repeat of the frame and digipeats the
frame, decrementing flood to ―FLOOD4-2.‖ It didn't digipeat its own ―FLOOD4-4" frame
because it can't hear itself! Station B finishes last due to the slot/persist algorithm. D
digipeats the frame only once even though it hears both B's and C's transmissions since
they are within 30 seconds of its own transmission.
Bibliography
For more information on the Global Positioning System, we recommend the following
resources:
General Information
Bruninga, Bob, WB4APR, ―Automatic packet reporting system (APRS)‖, 13
Digital Communications Conference Proceedings, 1994. (address: ARRL, 225 Main
Street, Newington, CT, 06111).
Horzepa, Stan, ―Getting On Track with APRS,‖ ARRL (225 Main Street, Newington, CT
06111) 1996.
Sproul, Keith, WU2Z, ―MacAPRS‖, 13th ARRL Digital Communications Conference
Proceedings, 1994.
Technical Information
Collins, J., et al., GPS Theory and Practice, Second Edition, Springer-Verlag, 1993.
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ARRL