aprsmon(8)

1APRSMON(8)                 Linux Programmer's Manual                APRSMON(8)
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NAME

6       aprsmon - monitor APRS AX.25 traffic for javAPRS
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SYNOPSIS

9       aprsmon [-a] [-m] [-r] [-k minutes] [-p port] [-t title] [-i infofile]
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DESCRIPTION

12       Aprsmon uses SOCK_PACKET facilities to provide a network monitor of all
13       AX.25 UI text traffic heard by the system.  It is based on listen(1).
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15       Aprsmon collects (-m) or displays standard AX.25 UI text  frames  in  a
16       format  similar  to  that output by a standard TNC in "Monitor ON" mode
17       and is intended to be used with programs like javAPRS which wish to see
18       a  TNC  data stream over a TCP connection.  When the aprsmon master has
19       been running for a while and a new aprsmon slave starts up,  first  all
20       saved  up  reports are sent, then a title line indicating the beginning
21       of live data is sent, and new reports are sent as received.
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23       Compressed position and telemetry reports as generated by the APRS  Mic
24       Encoder  are  translated into the conventional uncompressed APRS Micro-
25       Interface-Module (MIM) telemtry format so that these stations are visi‐
26       ble  in  javAPRS.   Reports  containing a TheNet X1J4 beacon header are
27       also edited to strip off the  header  making  these  nodes  visible  in
28       javAPRS as well.
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OPTIONS

31       -a        Allow for the monitoring of outgoing frames as well as incom‐
32                 ing ones.
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34       -r        Choose "raw" mode which allows non-printable data through.
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36       -p port   Monitor only those frames received on a particular  port,  by
37                 default all AX.25 interfaces are monitored.
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39       -m        "Master"  mode.  Retain monitored data for the number of min‐
40                 utes specified with the -k option in a shared memory segment.
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42       -k minutes
43                 Retain monitored packets going back the given number of  min‐
44                 utes.  Default is 30.
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46       -t title  Sets  the  javAPRS  title string.  Default is "Live data from
47                 Linux."
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49       -i infofile
50                 Infofile is the path to the  file  that  the  aprsmon  master
51                 writes  the  shared  memory  segment and semaphore id's into.
52                 Default is "/var/ax25/aprsmon.info."
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javAPRS CONFIGURATION

55       Set up one aprsmon master running on your system to collect  historical
56       data  going  back  a  while.   You  will  probably  want  to  set up an
57       /etc/rc.d/init.d script for this.
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59       aprsmon -a -m&
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61       Add an entry into /etc/services with the port number you  want  javAPRS
62       to connect on.  For example:
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64       aprs      14439/tcp # APRS monitor on 144.39
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66       Add an entry into /etc/inetd.conf for this service:
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68       aprs stream tcp nowait root /usr/sbin/aprsmon aprsmon -a
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70       To test, simply "telnet localhost aprs".  To use with javAPRS, set, for
71       example,
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73       <PARAM name = "dataFile1" value = "netc:14439:localhost">
74       in your HTML file as described in the javAPRS documentation,  and  then
75       use appletviewer to run javAPRS:
76       appletviewer mydemo.html
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Mic-E to MIM Translation

80       The  Mic-E reduces the duration of packet noise on a voice frequency by
81       encoding its data in a compressed form, some of which is binary.   Some
82       APRS-decoding  software,  notably  javAPRS, is unable to deal with this
83       data.  To solve this problem aprsmon expands the Mic-E packet into  one
84       or two MIM packets as follows:
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86       @ddhhmmzDDMM.hhN/DDDMM.hhW$cse/spd/E>mon/Mm/status
87       T#MIC,aaabbbcccdddeeefffComments
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90       ddhhmm    is  the  UTC day and time the packet was received by the host
91                 running aprsmon.
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93       DDMM.hhN  is the latitude.
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95       /         is the symbol table selection (/ or \).
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97       DDDMM.hhW is the longitude.
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99       $         is the symbol.
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101       cse,spd   are course and speed.
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103       E         is the type of Mic-Encoder:
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105                 E - TAPR Mic-Encoder
106                 T - Kenwood TH-D7
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108       m         is the status message number, and
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110       status    is the status message number expanded as follows:
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112                 0 -  Off duty..
113                 1 -  Enroute...
114                 2 -  In Service
115                 3 -  Returning.
116                 4 -  Committed.
117                 5 -  Special...
118                 6 -  PRIORITY..
119                 7 -  EMERGENCY.
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121       aaa,bbb,ccc,ddd,eee,fff
122                 are the values of the telemetry channels.
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FILES

125       /etc/ax25/axports /var/ax25/aprsmon.info
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AUTHOR

133       Alan Crosswell, n2ygk@weca.org
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137Linux                           9 February 1999                     APRSMON(8)