SCS PTC-IIex, Manual

Page: 114 / 220

8 FAX
8.4 Fax:-menu commands
When in the main-menu (
cmd
:
-prompt), the
FAX
-command leads to the
fax:-
menu. The
menu announces itself only with the prompt
fax
:
(the description
fax:
is misleading
because within this menu additional modes are available). In the
fax:-
menu the following
commands are available:
Amfax
,
Fmfax
,
Jvfax
,
JVComm
,
Sstv
,
FSk
,
Comparator
,
PR300
,
AGain
,
AResolut
,
FResolut
,
SResolut
,
FSKBAud
,
Deviation
,
MBaud
,
SMode
,
TXcomp
,
HSynch
,
JSynch
,
ASynch
.
All other ( normal ) commands are not available in the
fax:-
menu!
Quit
or
DD
exit the
fax:-
menu.
All commands in the
fax:-
menu may also be carried out from the main menu, by setting
the prefix FAX before the actual command.
cmd:
FAX
JVFAX <Return>
This is corresponding with the usual convention of the other sub-menus, e.g
. sys:-
menu.
The
fax:-
menu consists of two basic types of commands, the MODEM commands and
the PARAMETER commands.
The carrying out of a Modem command sets the PTC-IIex into the actual
FAX/SSTV/AUX modem function. It loads the appropriate new routines into the signal
processor, adjusts the tuning indicator to the new function and at once starts passing the
demodulated signal to the RS-232 interface - which may have had its baud rate changed
during the Modem command, refer to the
MBaud
-Parameter command.
The MODEM operation of the PTC-IIex can be ended at any time by inputting a byte
with the value 255 (dec.) via the RS-232 port. It is essential to use the correct baud rate
(see
MBaud
-command!). After the ending of Modem operation, the PTC-IIex announces
itself with the normal
cmd:-
prompt, and is at once in the main menu. The baud rate is
automatically returned to the value it was before the Modem command was called.
The PARAMETER commands are used for setting the various values needed for the
particular Modem mode chosen, e.g. the actual baud rate during Modem operation
(
MBaud
), the deviation for FM-FAX (
Deviation
), or the internal amplification for
AM-FAX (
AGain
parameter).
The Parameters must be set before the start of the chosen Modem function! During
MODEM operation, the Parameter commands are not available; only the change of
particular operating parameters in the operating mode
JVFAX
is possible using special
control-codes (refer to the
JVFAX
modem command).
Note concerning the data-rate during MODEM operation:
The received data is sent with the maximum possible speed to the serial interface in all
MODEM operating modes. There are no pauses between the individual characters, not
even through excessive use of the Packet-Radio function of the PTC-IIex multi-tasking.
With an
MBaud
-rate for example, of 57600 bits/sec, there is a new value available for the
connected PC approximately every 170
μ
sec (10 steps of 1/57600 sec per step). A
guarantee of modem data synchronization over a long period, cannot however be given.
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