Timewave DSP-232, Operating Manual, Page: 78 / 271

Chapter 5 Packet Operation
I-frames, until it receives a polling frame from the master. The slave station may only send an I-frame to the master
after a poll frame has been received.
The packet timing of the master station is critical for proper meteor scatter operation. In a normal AX.25 packet
connect, the
FRACK timer counts down until it reaches zero and then a RETRY of a poll frame is sent. The
FRACK
timer counts in units of seconds, however, and a finer timing resolution is desirable for meteor scatter
work. A new timer, called FRICK, has been added which times in 10 mS increments. The FRICK timer can be set
from 0 (disabled) to 250 which corresponds to a time of up to 2.5 seconds.
The following settings are recommended for this method of meteor scatter work. Both packet stations should use the
same settings:
UBIT 18 ON
RETRY 0
AX25L2V2 ON
MAXFRAME 1
(
CHECK
doesn’t matter)
FRICK n , where n is large enough to allow the other station time to send the start of an acknowledgment
frame.
Note : Don’t operate the unit with multiple packet connections while
FRICK
is active (1-250). In contrast to
FRACK , which provides one retry timer per multi-connect channel, there is only one FRICK timer in the
DSP. Each logical channel will try to use the same
FRICK
timer, causing interference to the operation of
the other channels.
Digipeaters shouldn’t be used when in the meteor scatter mode. The
FRICK timer (unlike FRACK ) doesn’t allow
any extra time when digipeater stations are specified. To return to normal AX.25 packet operation, turn
UBIT 18
OFF . Also, be sure to disable the FRICK timer (by setting FRICK to 0 ) when you’re through operating in meteor
scatter mode.
Intermediate and Advanced Packet Commands
Your DSP has many commands that are not necessary for day-to-day connects or casual conversations. Still, as you
become more familiar with packet, these commands and features may become important to you.
1200/9600 bps Operation
To select the speed you want to operate packet at on VHF, simply change the value of
HBAUD
--for 1200 bps
packet, enter HBAUD 1200 ; for 9600 bps packet, enter HBAUD 9600 .
Monitoring Other Stations While—or While Not—Connected
When you’re connected,
MCON
determines what packets are shown. The default of
MCON
is
0
(zero) which tells
the DSP’ not to monitor any packets while you’re connected. Most users prefer it this way so they’re not disturbed
with monitored channel data while they’re connected with another station. However, if you want to monitor packets
while connected, refer to
MCON
for user settings.
Use the
MONITOR command to determine what kinds of packets you’ll see when you’re not connected to any
stations. The higher the argument number (1-6), the more information you’ll see. If you don’t want to see
extraneous information associated with sent packets, use a lower value like
2
or
3
.
Note : If you’ll be leaving your DSP on to accept connects from other stations while your computer is off, set
MONITOR to 0 (zero). This way, you won’t fill up the DSP’s buffer with “junk” copy and will devote its
memory to its MailDrop.
September, 05 5-17