Ubuntu Manpage: remotetrx.conf - Configuration file for the SvxLink remote transceiver server

NAME

       remotetrx.conf - Configuration file for the SvxLink remote transceiver server

DESCRIPTION

remotetrx is the SvxLink remote transceiver server. This man-page describe the configuration file format
for it.

The RemoteTrx application can handle more than one transceiver at a time. You may for example want to
handle both a 2m and a 70cm receiver on a site. One sound card is sufficient for doing this since the
left channel can be used for one receiver and the right channel can be used for the other receiver. The
GLOBAL/TRXS configuration variable is used to tell the RemoteTrx application which transceivers to set
up. Each transceiver have an uplink that is used to interface to the main SvxLink server. The most common
type is the net uplink which link to the main SvxLink server over the Internet using TCP/IP. It is also
possible to have an uplink via RF but the functionality is then limited.

The term "uplink" might be a bit confusing for some people. In this case it does not refer to any
specific direction in which the data or audio is flowing. It's just the name for the link up to the main
SvxLink server.

RemoteTrx look for configuration files in a number of places. First it tries to find a user specific
configuration file. It will look for a user specific configuration file in two places:
$HOME/.svxlink/remotetrx.conf. If no user specific configuration file can be found, remotetrx will look
for the system wide configuration file /etc/svxlink/remotetrx.conf. The --config command line option may
also be used to specify an arbitrary configuration file.

FILE FORMAT

       The configuration file is in the famous INI-file format. A generic example of how such a file might  look
       like is shown below.

         [SECTION1]
         VALUE1=1
         VALUE2="TWO "
         VAULE3="Multi "
                "line"

         [SECTION2]
         VALUE1=2

       This  is  a  simple  format  that  contain name=value pairs that belong to a section.  In written text, a
       specific configuration variable can be referred to as  SECTION1/VALUE2  meaning  "configuration  variable
       VALUE2 in section SECTION1".

       The  same  variable name can exist in two different sections. For example VALUE1 in section SECTION1 have
       the value 1 and VALUE1 in section SECTION2 have the value 2. Values containing spaces at the beginning or
       end of the line must be surrounded by citation characters (see SECTION1/VALUE2). Likewise  with  a  multi
       line value (see SECTION1/VALUE3).

CONFIGURATION VARIABLES

Here is the description of all configuration variables that remotetrx understands. The configuration
variables are described section for section.

GLOBAL
The GLOBAL section contains application global configuration data.

TRXS This configuration variable specify a comma separated list of transceiver configuration sections.

CFG_DIR
Specify the path to a directory that contain additional configuration files. If a relative path
is specified, the path will be relative to the directory where the main configuration file is at.
All files in the specified directory will be read as additional configuration. Filenames starting
with a dot are ignored.

TIMESTAMP_FORMAT
This variable specifies the format of the timestamp that is written in front of each row in the
log file. The format string is in the same format as specified in the strftime(3) manual page. The
default is "%c" which is described as: "the preferred date and time representation for the current
locale". The environment variables LC_TIME, LC_ALL and LANG will affect how this time format will
look. For example, setting LC_TIME="sv_SE.UTF8" will give you swedish timestamp representation.
Other examples of format specifiers are:

• %d - The day of the month as a decimal number (range 01 to 31)

• %b - The abbreviated month name according to the current locale

• %Y - The year as a decimal number including the century

• %H - The hour as a decimal number using a 24-hour clock (range 00 to 23)

• %M - The minute as a decimal number (range 00 to 59)

• %S - The second as a decimal number (range 00 to 61)

So, TIMESTAMP_FORMAT="%d %b %Y %H:%M:%S" would give a timestamp looking something like: "29 Nov
2005 22:31:59".

CARD_SAMPLE_RATE
This configuration variable determines the sampling rate used for audio input/output. SvxLink
always work with a sampling rate of 16kHz internally but there still are som benefits from using a
higher sampling rate. On some sound cards the filters look pretty bad at 16kHz and the amplitude
response will not be uniform which among other things can cause problems for the software DTMF
decoder.

Some sound cards also sound very bad at 16kHz due to insufficient anti-alias filtering or
resampling effects. These, often cheeper, sound cards sound OK at 48kHz.

The downside of choosing a higher sampling rate is that it puts a little bit more load on the CPU
so if you have a very slow machine (<300MHz), it might not have the computational power to handle
it.

Supported sampling rates are: 16000 and 48000.

CARD_CHANNELS
Use this configuration variable to specify how many channels to use when opening a sound card. For
normal sound cards the only practical values to use are 1 for mono and 2 for stereo. The latter is
the default.

When using the sound card in stereo mode it is possible to use the left and right channels
independenly to drive two transceivers. When using the sound card in mono mode, both left and
right channels transmit/receive the same audio.

Network uplink transceiver section
The network uplink transceiver section is used to specify the configuration for a network link to the
main SvxLink server. In the default configuration file there is a network uplink transceiver section
called NetUpLinkTrx.

TYPE Always "Net" for a network uplink transceiver configuration section.

RX Point out the receiver configuration section to use. Set to NONE if no RX is used. A receiver is
configured in the exact same way as in the SvxLink server. Have a look at svxlink.conf(5) for
more information on how to configure a receiver.

TX Point out the transmitter configuration section to use. Set to NONE if no TX is used. A
transmitter is configured in the exact same way as in the SvxLink server. Have a look at
svxlink.conf(5) for more information on how to configure a transmitter.

LISTEN_PORT
The TCP port to listen on. Make sure to choose a unique port for each network uplink transceiver
configuration. The default is 5210.

AUTH_KEY
This is the authentication key (password) to use to athenticate incoming connections. The same key
have to be specified in the client configuration. If no key is specified, all logins will be
unauthenticated. A good authentication key should be 20 characters long. The key will never be
transmitted over the network. A HMAC-SHA1 challenge-response procedure will be used for
authentication.

MUTE_TX_ON_RX
If set to a value >= 0, will stop the transmitter from transmitting when the squelch is open. The
value represents a delay, in milliseconds, after the squelch has closed, that the transmitter will
be muted. For example, if set to 1000, the transmitter will be muted one second after the squelch
has closed. The default is not to mute the transmitter when the squelch is open.

RF uplink transceiver section
The RF uplink transceiver configuration section is used to specify the configuration for an RF link to
the main SvxLink server. In the default configuration file there is an RF uplink transceiver section
called RfUpLinkTrx. The section name could be anything. It should match what is specified in the TRXS
configuration variable in the GLOBAL section.

The use of Rf uplinks is very EXPERIMENTAL and still have some flaws. Among other things, detected tones
(like CTCSS or 1750 tone burst) are not relayed and all relayed DTMF tones are always 100ms long no
matter how long the received digit was. Signal level measurements are not relayed either.

Any way, it's used to link remote receivers coming in on the Internet to a site that do not have access
to Internet.

TYPE Always "RF" for an RF uplink transceiver configuration section.

UPLINK_TX
Point out the uplink transmitter configuration section to use. The configuration for an uplink
transmitter looks exactly the same as for any other transmitter. In the default configuration
file there is an uplink transmitter configuration section called UplinkTx. If there is no uplink
transmitter, specify NONE.

UPLINK_RX
Point out the uplink receiver configuration section to use. The configuration for an uplink
receiver looks exactly the same as for any other receiver. In the default configuration file
there is an uplink receiver configuration section called UplinkRx. If there is no uplink
receiver, specify NONE.

MUTE_UPLINK_RX_ON_TX
Specify if the link receiver should be muted or not when the link transmitter is transmitting. Set
it to 0 if a full duplex link is desired. Default is 1.

LOOP_RX_TO_TX
Set to 1 to loop incoming RX audio (not link RX) directly to the TX (not link TX). You figure out
when to use it. Default is 0.

FALLBACK_REPEATER
This function is useful if running RemoteTrx as both RX and TX for a repeater. If the connection
to the SvxLink base station is lost due to network errors, the RemoteTrx provides a very basic
repeater function (SQLELCH controlled) until the the connection has been established again. Set to
1 to enable this function or set to 0 to disable it. Default is 0.

FILES

       /etc/svxlink/remotetrx.conf (or deprecated /etc/remotetrx.conf)
              The system wide configuration file.

       ~/.svxlink/remotetrx.conf
              Per user configuration file.

       /etc/svxlink/remotetrx.d/*
              Additional configuration files.

AUTHOR