Page 29 of 101
DWG ID: 181-0101-00A
Date: 2003-09-26
To change streams, to make another connect or to direct data to another connected station
on a different stream, type the STREAMSW character, and the letter designation of the
desired stream. No return or enter key is necessary.
The setting of STREAMEV will then determine how often the stream designator is
displayed with received data. Setting it to ON will make the stream designators show on
every connected packet received. Setting STREAMCA also to ON will add the callsign
of the "from" station beside the stream designator.
8.9
Timing
Dwait vs. Persistence and Slottime
When the TALON acts as a digipeater, received packets that need to be relayed are
retransmitted as soon as the frequency is clear. Beacon and other unproto packets to be
transmitted are normally delayed by a small amount of time, by the
PERSISTENCE/SLOTTIME algorithm or DWAIT.
The default value for DWAIT is set to zero. If the DWAIT method is used, the TALON
sending non-digipeat packets will wait for DWAIT (times 10 milliseconds) time of clear
channel before beginning to key-up the radio to transmit.
The PERSIST/SLOTTIME algorithm helps avoid packet collisions by randomizing the
wait time before transmitting. By using this random timing, it is less likely that any two
TALONs will transmit at the same time, causing a packet collision. When a TALON has
a packet to transmit and detects that the channel is clear, it will wait SLOTTIME (times
10 ms), and generate a random number. If resulting number is smaller than the number
specified by the setting of PERSIST, the packet will be transmitted. If the number is
larger, it will wait another SLOTTIME and then generate another random number and
again decide whether to transmit or not.
When using PERSIST/SLOTTIME, DWAIT should be set to 0, since both will be used if
specified.
8.10
FRACK (Frame Acknowledgment Time)
If the TALON expects an acknowledgment of a packet it has sent, it will wait FRACK
seconds for the acknowledgment. If the acknowledgment is not received it will either
send a poll or retransmit the packet, depending on the setting of AX25L2V2. When digis
are used, extra time is allowed for each transmission using the following equation:
FRACK * ((2 * n) + 1) s
where n is the number of digipeaters and s is the SI symbol for seconds. The length of the
packet transmitted (determined by PACLEN and MAXFRAME) also needs to be taken
into account when deciding how to set FRACK. Longer packets (and more of them)