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CHAPTER 3
OPERATION UNDER WINDOWS
3-16
Data can be pre-programmed in the ten programmable messages, or as text files on a disk. You can use
Load TX Buffer on the Files menu or press [Ait]-L to load a file from disk that does not exceed the 250
line capacity of the buffer. For files larger than the TX buffer, use the Send From Disk option of the Files
menu. Files sent that way are transmitted directly, rather than through the TX buffer.
ARQ END Commands: There are two methods of ending a CLOVER-II ARQ Link
1. Pressing [F7] or clicking DISC on the toolbar breaks the link in the normal manner after all pending text
has been sent. The link does not drop until the other station has confirmed receipt of the disconnect
request.
2. Pressing [Ait]-F7,[Ctri]-F7,or clicking PANIC produces similar action to [F7] except that all pending
transmit data is abandoned and a disconnect request is issued immediately. Use this key combination
only if you need to get off-the-air very quickly! Use of PANIC may force the other station to "retry out".
Initiating an ARQ CQ: To initiate an ARQ CQ call, press [Ait]-F9. The DXP38 will begin sending the
CLOVER-II CQ sequence, a special version of the CCB ARQ format. The number of CQ calls is set with
the "Fail Retries" parameter on page 1 of the configuration file (see Figure 4.8). Other CLOVER stations
on your frequency will see a message at the top left of their screen "ARQ CQ from (your call)".
Answering an ARQ CQ: To answer an ARQ CQ call, press [Ctri)-F9. Your station will respond by linking
to the calling station and you will see the other station's call at the top of your screen. If a CQ CCB is
received, your transceiver is already tuned close enough in frequency to link. Use the Frequency Error Bar
to fine tune after the link is established.
If a CCB fails to decode during the connect process, it will cause both stations to return to standby mode,
regardless of the retry counters. Once a connection is established it will hold together very tenaciously.
Performance Hints For Keyboarders: If there are fewer than 256 characters pending, they will be sent
using the "slow" CCB "Chat Mode". As soon as you exceed 255 pre-buffered transmit characters,
CLOVER-II will "shift gears" and begin transmitting data in large data blocks using faster modulation forms.
Block mode transmission will continue until all pending transmit text has been sent. Wilen all available data
has been sent, CLOVER will return to "Chat Mode". If you wish to immediately shift out of "Chat mode"
to higher rate modes, preload the transmit buffer with at least 255 characters (about 3 1/2 lines) -a fully-
loaded HERE IS message may be used for this purpose.
CLOVER-II is bi-directional. Both operators may type at the same time and data will be sent in both direc-
tions automatically without use of "OVER" commands. This feature works both in "Chat Mode" and in
long-block ARQ data mode.
3.15.4 FEC Mode
Wllile ARQ is the prevailing means of communications within CLOVER-II for passing traffic and general
conversation, occasionally there is a need for a "one-station-to-many" broadcast. The FEC mode serves
to provide just such a service. Any station tuned to the frequency of the FEC transmission will be able to
monitor it. Errors are corrected at the receiving station, although it is not possible to request repeats. Also,
FEC is not adaptive so you must make some judgement about current band conditions and select the mod-
ulation for your FEC transmission. The modulation you select can be changed during transmission.
Modulation modes: 2DPSM, BPSM, QPSM, 8PSM, 8P2A, 16P4A
In general, more robust modes for poor band conditions are the slower modulation rates (the first few in
the above list).
HAL990308
DXP38 MANUAL
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