'\"
'\" Copyright (c) 2007 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Device manual page for owtap -- 1-wire filesystem package
'\" Protocol sniffer for owserver tcp protocol
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\"
.TH OWTAP 1 2007 "OWTAP Manpage" "One-Wire File System"
.SH NAME
.B owtap
\- Packet sniffer for the owserver protocol 
.SH SYNOPSIS
.B owtap
.I \-p
owtap-tcp-port
.I \-s
owserver-tcp-port
.br
.SH "DESCRIPTION"
'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Program manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\"
.SS 1-Wire
.I 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.
.PP
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.
.PP
The 1-wire scheme uses a single 
.I bus master
and multiple
.I slaves
on the same wire. The bus master initiates all communication. The slaves can be 
individually discovered and addressed using their unique ID.
.PP
Bus masters come in a variety of configurations including serial, parallel, i2c, network or USB
adapters.
.SS OWFS design
.I OWFS
is a suite of programs that designed to make the 1-wire bus and its
devices easily accessible. The underlying principle 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.
.PP 
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 fundamental goal has been ease of use, flexibility
and correctness rather than speed.
.SS owserver
.B owserver (1)
is the backend component of the OWFS 1-wire bus control system.
.B 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
.B owserver (1)
over network sockets (tcp port).
.PP
Frontend clients include a filesystem representation:
.B owfs (1)
, and a webserver:
.B owhttpd (1).
Direct language bindings are also available, e.g:
.B owperl (3).
.PP
There are also many light-weight clients that can only talk to 
.B owserver (1)
and not to the 1-Wire bus directly. They include shell and multiple language modules (perl, Visual Basic, python,...)
.SS owserver protocol
All the
.B owserver (1)
clients use the
.B owserver protocol
for communication. The
.B owserver protocol
is a well documented tcp/ip client/server protocol. Assigned the "well known port" default of 4304. 
.SS owtap
.B owtap (1)
is interposed between
.B 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.
.SH SPECIFIC OPTIONS
.SS \-p
TCP port or IPaddress:port for
.I owtap
.br
Other OWFS programs will access owtap via this address. (e.g. owdir \-s IP:port /)
.SS \-s
TCP port or IPaddress:port for
.I owserver
.br
The tcp port (IP:port) for the "upstream" owserver.
.SH EXAMPLE
If
.B owserver (1)
is started:
.br
.B owserver \-p 4304 \-d /dev/ttyS0
.br
owserver on tcp port 4304 and connects to a physical 1-wire bus on a serial port.
.PP
You can directly query 
.B owserver (1)
with
.br
.B owdir \-s 4304 /
.PP
To see the protocol in action:
.br
.B owtap \-s 4304 \-p 3000
.br
.B owdir \-p 3000 /
.PP
In this case 
.B owtap (1)
is connecting to
.B owserver (1)
on the original port (4304) and offering a new port (3000) for clients.
.SH PLATFOMS
.B owtap (1)
is a pure
.I Tcl/TK
program and will run wherever
.I Tcl/TK
is available (Windows, Macintosh, Linux, Unix)
.SH LINKS
.SS owserver protocol
http://www.owfs.org/index.php?page=owserver-protocol
.SS Tcl/TK
http://www.tcl.tk
.SH SEE ALSO
.SS Programs
.B owfs (1) owhttpd (1) owftpd (1) owserver (1)
.B owdir (1) owread (1) owwrite (1) owpresent (1)
.B owtap (1)
.SS Configuration and testing
.B owfs (5) owtap (1) owmon (1)
.SS Language bindings
.B owtcl (3) owperl (3) owcapi (3)
.SS Clocks
.B DS1427 (3) DS1904(3) DS1994 (3) DS2404 (3) DS2404S (3) DS2415 (3) DS2417 (3)
.SS ID
.B DS2401 (3) DS2411 (3) DS1990A (3)
.SS Memory
.B 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)
.SS Switches
.B DS2405 (3) DS2406 (3) DS2408 (3) DS2409 (3) DS2413 (3) DS28EA00 (3)
.SS Temperature
.B DS1822 (3) DS1825 (3) DS1820 (3) DS18B20 (3) DS18S20 (3) DS1920 (3) DS1921 (3) DS1821 (3) DS28EA00 (3) DS28E04 (3)
.SS Humidity
.B DS1922 (3)
.SS Voltage
.B DS2450 (3)
.SS Resistance
.B DS2890 (3)
.SS Multifunction (current, voltage, temperature)
.B DS2436 (3) DS2437 (3) DS2438 (3) DS2751 (3) DS2755 (3) DS2756 (3) DS2760 (3) DS2770 (3) DS2780 (3) DS2781 (3) DS2788 (3) DS2784 (3)
.SS Counter
.B DS2423 (3)
.SS LCD Screen
.B LCD (3) DS2408 (3)
.SS Crypto
.B DS1977 (3)
.SS Pressure
.B DS2406 (3) -- TAI8570
.SH AVAILABILITY
http://www.owfs.org
.SH AUTHOR
Paul Alfille (paul.alfille@gmail.com)