NAME

       owtap - Packet sniffer for the owserver protocol

SYNOPSIS

       owtap -p owtap-tcp-port -s owserver-tcp-port

DESCRIPTION

   1-Wire
       1-wire  is  a  wiring  protocol  and series of devices designed and manufactured by Dallas
       Semiconductor, Inc. The bus is a low-power low-speed low-connector scheme where  the  data
       line can also provide power.

       Each  device  is  uniquely  and  unalterably numbered during manufacture. There are a wide
       variety of devices, including memory, sensors (humidity,  temperature,  voltage,  contact,
       current),  switches,  timers  and  data  loggers.  More complex devices (like thermocouple
       sensors) can be built with these basic devices. There are also 1-wire  devices  that  have
       encryption included.

       The  1-wire  scheme uses a single bus master and multiple slaves on the same wire. The bus
       master initiates  all  communication.  The  slaves  can  be  individually  discovered  and
       addressed using their unique ID.

       Bus  masters  come in a variety of configurations including serial, parallel, i2c, network
       or USB adapters.

   OWFS design
       OWFS is a suite of programs that designed to make the 1-wire bus and  its  devices  easily
       accessible.  The underlying priciple is to create a virtual filesystem, with the unique ID
       being the directory, and the individual properties of the device are represented as simple
       files that can be read and written.

       Details of the individual slave or master design are hidden behind a consistent interface.
       The goal is to provide an easy set of tools for a software designer to  create  monitoring
       or  control  applications.  There are some performance enhancements in the implementation,
       including data caching,  parallel  access  to  bus  masters,  and  aggregation  of  device
       communication.  Still  the  fundemental  goal  has  been  ease  of  use,  flexibility  and
       correctness rather than speed.

   owserver
       owserver (1) is the backend component of the OWFS 1-wire bus control system.  owserver (1)
       arbitrates  access  to the bus from multiple client processes. The physical bus is usually
       connected to a serial or USB port, and  other  processes  connect  to  owserver  (1)  over
       network sockets (tcp port).

       Frontend  clients include a filesystem representation: owfs (1) , and a webserver: owhttpd
       (1).  Direct language bindings are also available, e.g: owperl (3).

       There are also many light-weight clients that can only talk to owserver (1) and not to the
       1-Wire bus directly. They include shell and multiple language modules (perl, Visual Basic,
       python,...)

   owserver protocol
       All the owserver (1) clients use the owserver protocol  for  communication.  The  owserver
       protocol  is  a  well  documented  tcp/ip client/server protocol. Assigned the "well known
       port" default of 4304.

   owtap
       owtap (1) is interposed between owserver (1) and clients,  to  display  and  help  resolve
       communication  problems.  Network  communication  is  forwarded  in both directions, but a
       visual display is also created, with statistics and "drill-down" of individual packets.

SPECIFIC OPTIONS

   -p
       TCP port or IPaddress:port for owtap
       Other OWFS programs will access owtap via this address. (e.g. owdir -s IP:port /)

   -s
       TCP port or IPaddress:port for owserver
       The tcp port (IP:port) for the "upstream" owserver.

EXAMPLE

       If owserver (1) is started:
       owserver -p 4304 -d /dev/ttyS0
       owserver on tcp port 4304 and connects to a physical 1-wire bus on a serial port.

       You can directly query owserver (1) with
       owdir -s 4304 /

       To see the protocol in action:
       owtap -s 4304 -p 3000
       owdir -p 3000 /

       In this case owtap (1) is connecting to owserver (1)  on  the  original  port  (4304)  and
       offering a new port (3000) for clients.

PLATFOMS

       owtap  (1)  is  a pure Tcl/TK program and will run whereever Tcl/TK is available (Windows,
       Macintosh, Linux, Unix)

LINKS

   owserver protocol
       http://www.owfs.org/index.php?page=owserver-protocol

   Tcl/TK
       http://www.tcl.tk

SEE ALSO

   Programs
       owfs (1) owhttpd (1) owftpd (1) owserver (1) owdir (1) owread (1)  owwrite  (1)  owpresent
       (1) owtap (1)

   Configuration and testing
       owfs (5) owtap (1) owmon (1)

   Language bindings
       owtcl (3) owperl (3) owcapi (3)

   Clocks
       DS1427 (3) DS1904(3) DS1994 (3) DS2404 (3) DS2404S (3) DS2415 (3) DS2417 (3)

   ID
       DS2401 (3) DS2411 (3) DS1990A (3)

   Memory
       DS1982  (3)  DS1985  (3) DS1986 (3) DS1991 (3) DS1992 (3) DS1993 (3) DS1995 (3) DS1996 (3)
       DS2430A (3) DS2431 (3) DS2433 (3) DS2502 (3) DS2506 (3) DS28E04 (3) DS28EC20 (3)

   Switches
       DS2405 (3) DS2406 (3) DS2408 (3) DS2409 (3) DS2413 (3) DS28EA00 (3)

   Temperature
       DS1822 (3) DS1825 (3) DS1820 (3) DS18B20 (3) DS18S20 (3) DS1920 (3) DS1921 (3) DS1821  (3)
       DS28EA00 (3) DS28E04 (3)

   Humidity
       DS1922 (3)

   Voltage
       DS2450 (3)

   Resistance
       DS2890 (3)

   Multifunction (current, voltage, temperature)
       DS2436  (3)  DS2437  (3) DS2438 (3) DS2751 (3) DS2755 (3) DS2756 (3) DS2760 (3) DS2770 (3)
       DS2780 (3) DS2781 (3) DS2788 (3) DS2784 (3)

   Counter
       DS2423 (3)

   LCD Screen
       LCD (3) DS2408 (3)

   Crypto
       DS1977 (3)

   Pressure
       DS2406 (3) -- TAI8570

AVAILABILITY

       http://www.owfs.org

AUTHOR

       Paul Alfille (paul.alfille@gmail.com)