Wavecom W 4010 User Manual page 16

The amateur radio standard AX.25 has been derived from the commercial standard (CCITT X.25, ISO HDLC).
Amateur packet radio has spread rapidly, due to the initiative of an American club T.A.P.R. Packet-Radio is a
synchronous transmission. The data is usually sent as ASCII characters.
With packet radio information is conveyed in blocks (frames) as follows:
Flag
A flag, consisting of the sequence 01111110, is sent at the beginning and at the end of every block.
The address can have up to 80 characters, usually only 16 or 24 are used (direct connection or via 1 repeat-
er). The AX.25 standard has several different frame types, three of which are the I, S and U frames. Infor-
mation is almost always transmitted in I frames, seldom in U frames. The S and U frames are used in con-
trolling and monitoring the transmission progress. The data field can contain up to 256 characters, and as
the transmission is transparent all characters and character combinations are allowed. The FCS field contains
the check sum.
[F1]
[F2]
[F3]
[F4]
[F4]+[F3]
[F1]+[F2]
[F2]+[F3]
[BU-ZI]+[F1]
[BU-ZI]+[F2]
[BU-ZI]+[F3]
[BU-ZI]+[F4]
[BU-ZI]
A large number of stations around the word transmit weather charts at certain times. To print a picture it is
important that the printer has paper in it and is in the status ON LINE. Additionally the W 4010 push button
[PRINT] will have to be pushed (the LED [PRINT] MUST glow).
If it is desired to print the next picture, leave the W 4010 in the AUTO MODE, which is the default mode
after turn on. A weather picture needs 10 - 40 minutes and when the next picture starts, the LED [TRAFFIC]
will glow as the picture is being printed.
If it is desired to receive a chart transmission that has already started, choose an IOC value (usually 576) as
well as a drum speed. Thereafter push the [F1] key. A scale will first be printed and this can be used to cor-
rectly position the picture by using the PHASE key. In case the picture image is in negative (i.e. white on
black), choose the other sideband and tune in again. Weather FAX transmissions are sent in upper sideband
(USB or FAX). Before transmission is started, the key [BU-ZI] can be used to enable reception on LSB. When
the picture is finished printing, the W 4010 sends form feed to the printer after prints the information
"WAVECOM W 4010 WEATHER-FAX" on a row.
AUTO: The [F1] key is used to switch between automatic and manual chart reception. If switched to auto-
matic, the W 4010 chooses the correct values for IOC and RPM as well as starting a print-out of the synchro-
nization signal, the [TRAFFIC] LED glows; the [SYNCH] LED glows when the transmission begins.
MANUAL: This mode starts the printout by hand. For a short time, both [SYNCH] and [TRAFFIC] LEDs
glow, thereafter only the [TRAFFIC] LED glows. The values of IOC and RPM must, however, be manually set
beforehand. If the key [F1] is pushed again the print-out is terminated. The status line displays
mode.
DRUM SPEED: Used to adjust the drum speed RPM during reception by choosing 60, 90 or 120 RPM. The
chosen speed appears in the status line.
Address
WEATHER-FAX
AUTO/MANUAL
DRUM SPEED 60 / 90 / 120 RPM
IOC 288 / 576
go to next operating mode
go to previous operating mode
PHASE LEFT <<
PHASE RIGHT >>
FINE SPEED UP
FINE SPEED DOWN
PRINTER SELECT
FORM FEED ON/OFF
POLARITY POS-NEG
Control Data
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FCS Flag
AUTO as the