ZERK(1)

NAME
zerk - All purpose GREIS fitting

SYNOPSIS

zerk [-?] [-c command] [-d disable] [-e enable] [-f file/device] [-h] [-O oaf] [-p preset] [-R rawfile] [-r] [-S setspeed] [-s speed] [-V] [-v verbosity] [-W] [-w wait] [[server[:port[:device]]]]

DESCRIPTION

zerk is an all purpose GREIS fitting. If you do not have a Javad GPS that speaks the GREIS protocol then you can stop reading now.

This tool operates with your Javad GPS at a very low level. To understand zerk you must first be familiar with your Javad GPS and the documentation for the GREIS protocol. GREIS (GNSS Receiver External Interface Specification) Guide[1].

zerk can decode common GREIS messages, poll the GPS status, enable and disable GPS features, and send user generated commands to the GPS. It can read GREIS messages from a file. It can read and write directly through a serial device, or through a running gpsd instance.

OPTIONS

The program accepts the following options:

-?, -h
    Makes zerk print a usage message and exit.

-c COMMAND
    Send a text string to the GPS. Accepts one parameter, COMMAND, the command string to send to the GPS. The string is sent verbatim, except a newline is appended.

-d OPTION
    Disable an option in the GPS. Accepts one parameter, OPTION, the option to disable. zerk will exit after the GPS acknowledges the command, unless the -W is given.

    4HZ
        Disable basic GREIS messages at 4Hz. The messages are: [RT], [UO], [GT], [PV], [SG], [DP], [SI], [EL], [AZ], [EC], [SS], and [ET]

    COMPASS
        Disable use of the COMPASS (BeiDou) constellation.

    CONS
        Disable use of all constellations.

    DEFMSG
        Disable the default message set (/dev/msg) at 1Hz.

    GALILEO
        Disable use of the GALILEO constellation.

    GLONASS
        Disable use of the GLONASS constellation.

    GPS
        Disable use of the GPS constellation.

    IPR
        Disable all Integer Pseudo Range messages. These are [rx], [rc], [r1], [r2], [r3], [r5], [rl].

    IRNSS
        Disable use of the IRNSS constellation.

    NMEA
        Disable basic NMEA 4.1e messages at 4Hz. The messages are GBS, GGA, GSA, GST, GSV, RMC, VTG, and ZDA.

    QZSS
        Disable use of the QZSS constellation.

    SBAS
        Disable use of the SBAS constellation.

    SNR
        Disable all SNR messages, except [EC]. The messages disabled are: [E1], [E2], [E3], [E5], [El].

-e OPTION
    Enable an option in the GPS. Accepts one parameter, OPTION, the option to enable. zerk will exit after the GPS acknowledges the command, unless the -W is given. -e accepts the same OPTIONs as -d, except the action is to enable the option.

-f FILE
    Connect to a file or device. Accepts one parameter, FILE, the file or device to open. Files are opened read-only. Character devices are opened read/write, unless the -r parameter is given. Requires the pyserial module.

-O OAF
    Load an Option Authorization File (OAF) into the GPS. Accepts one parameter, OAF, command file to read. The OAF is just a special case of a '.jpo' (GREIS command file). -O will send any valid .jpo file to the GPS.

-p PRESET
    Send a preset command the GPS. Accepts one parameter, PRESET, the name of the command to send. zerk will exit after the GPS acknowledges the command, unless the -W is given.

    COLDBOOT
        Coldboot the GPS.

    CONS
        Poll the enabled constellations.

    DM
        Disable all periodic GREIS messages.

    ID
        Poll the receiver ID.

    IPR
        Poll all Integer Pseudo Range messages. These are [rx], [rc], [r1], [r2], [r3], [r5], [rl].

    OAF
        Poll all OAF options.

    RESET
        Reset (reboot) the GPS.

    SERIAL
        Poll receiver serial number.

    SNR
        Poll all Signal to Noise Ratio (SNR) messages. [EC], [E1], [E2], [E3], [E5], [El].

    VENDOR
        Poll GPS vendor.

    VER
        Poll GPS version.

-r
    Read only. Do not send anything to the GPS.

-R RAW
    Save all raw data from the GPS into the file RAW.

-S SPEED
    Configure the GPS serial speed to SPEED bps.

-s SPEED
    Set local serial port speed to SPEED bps. Default 115,200 bps.

-V
    Print zerk version and exit.

-v VERBOSITY
    Set verbosity level to VERBOSITY. Verbosity can be from 0 (very quiet), to 4 (very noisy). Default 2.

-W
    Force waiting the entire wait time. No early exit for completion of -d, -e or -p command.

-w WAIT
    Wait for WAIT seconds before exiting. Will exit early on command completion of -d, -e or -p command, unless -W is given. Default 2.0 second.

[server[:port[:device]]]
    By default, zerk collects data from all compatible devices on localhost, using the default GPSD port 2947. An optional argument may specify a server to get data from. A colon-separated suffix is taken as a port number. If there is a second colon-separated suffix, that is taken as a specific device name to be watched. Further details on the gps(1) man page.

ENVIRONMENT

Options can be placed in the ZERKOPTS environment variable. ZERKOPTS is processed before the CLI options.

EXAMPLES

Print current Javad serial portC of GPS connected to local running gpsd::

     zerk -c "print,/cur/term"

Decode raw log file:

    zerk -r -f greis-binary.log -v 2

Change GPS port speed of device on /dev/ttyAMA0 to 230,400 bps::

    zerk -S 230400 -f /dev/ttyAMA0

Watch entire GPS reset cycle:

    zerk -p RESET -v 2 -w 20 -W

Poll SVs Status:

    zerk -W -w 2 -v 2 -c "out,,jps/{CS,ES,GS,Is,WS,QS}"

Dump gpsd data from remote server:

    zerk -v 2 -w 5 server

SEE ALSO

zerk is written to conform to the official Javad documentation for the GREIS protocol. GREIS (GNSS Receiver External Interface Specification) Guide[1].

gpsd(8), gps(1), cgps(1), xgps(1), gpsfake(1), gpsctl(1), gpscat(1), gnuplot(1).

AUTHOR

Gary E. Miller<gem@rellim.com>

NOTES

1.  GREIS (GNSS Receiver External Interface Specification) Guide
    http://www.javad.com/downloads/javadgnss/manuals/GREIS/GREIS_Reference_Guide.pdf