GPS in port C1

It is possible to monitor the PPS signal from GPS and GPS data received, in case the GPS is connected to C1 port of GW6e (or Com1 in case of GWM). To debug the GPS, it is necessary to reach the command line interface.

This can be done via

1. GWS built-in SSH connection (GWS Setup window -> Set> Open remote terminal)
2. Other SSH connection to the Telem-GWx device
3. Telem-GW console port (mini-USB connector on the front panel)

To monitor the PPS signal received from GPS, log in as root and execute the command "ppswatch -a /dev/gpspps0" . The output will display a new line every second (if the PPS signal exists)

 
martem@telem-gwm ~ $ su
Password:
root@telem-gwm /home/martem $ ppswatch -a /dev/gpspps0
trying PPS source "/dev/gpspps0"
found PPS source "/dev/gpspps0"
timestamp: 1425049001, sequence: 3426, offset:  201638006
timestamp: 1425049002, sequence: 3427, offset:  201700698
timestamp: 1425049003, sequence: 3428, offset:  201766208
timestamp: 1425049004, sequence: 3429, offset:  201830650
timestamp: 1425049005, sequence: 3430, offset:  201897284
timestamp: 1425049006, sequence: 3431, offset:  202007480
timestamp: 1425049007, sequence: 3432, offset:  202036986
^C
Total number of PPS signals: 7
Maximum divergence: 202036986

If there is no PPS signal, the output will prompt a timeout, such as:

root@telem-gwm /home/martem $ ppswatch -a /dev/gpspps0
trying PPS source "/dev/gpspps0"
found PPS source "/dev/gpspps0"
time_pps_fetch() error -1 (Connection timed out)
time_pps_fetch() error -1 (Connection timed out)
^C
Total number of PPS signals: 0
Maximum divergence: 0

For debugging the data received from GPS, issue the command "cat /dev/gps0"

root@telem-gwm /home/martem $ cat /dev/gps0
$GPGSA,A,3,05,13,30,28,17,,,,,,,,3.5,2.8,2.1*35
$GPGSV,2,1,05,05,04,211,19,13,65,193,24,30,28,094,15,28,66,093,29*73
$GPGSV,2,2,05,17,20,141,27*49
$GPRMC,151211,A,5923.8643,N,02439.5178,E,000.5,357.8,270215,007.8,E*72
$GPGGA,151211,5923.8643,N,02439.5178,E,1,05,2.8,81.8,M,17.1,M,,*7F
$GPGSA,A,3,05,13,30,28,17,,,,,,,,3.5,2.8,2.1*35
$GPGSV,2,1,05,05,04,211,19,13,65,193,23,30,28,094,15,28,66,093,29*74
$GPGSV,2,2,05,17,20,141,27*49
$GPRMC,151212,A,5923.8643,N,02439.5177,E,000.5,357.8,270215,007.8,E*7E
$GPGGA,151212,5923.8643,N,02439.5177,E,1,05,2.8,81.9,M,17.1,M,,*72
$GPGSA,A,3,05,13,30,28,17,,,,,,,,3.5,2.8,2.1*35
$GPGSV,2,1,05,05,04,211,19,13,65,193,24,30,28,094,16,28,66,092,29*71
$GPGSV,2,2,05,17,20,141,27*49
$GPRMC,151213,A,5923.8643,N,02439.5177,E,000.5,357.8,270215,007.8,E*7F
$GPGGA,151213,5923.8643,N,02439.5177,E,1,05,2.8,81.9,M,17.1,M,,*73
$GPGSA,A,3,05,13,30,28,17,,,,,,,,3.5,2.8,2.1*35
$GPGSV,2,1,05,05,04,211,19,13,65,193,24,30,28,094,16,28,66,092,29*71
$GPGSV,2,2,05,17,20,141,27*49

Now you know when (UTC 27.02.2015 15:12:11)and where ( 59 23.8643 N 24 39.5178 E ) this example was created. If GPS data pin is not connected, there is no output from /dev/gps0