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DS2404(3)		      One-Wire File System		       DS2404(3)

NAME
     DS2404 - EconoRAM time chip

     DS2404S
	    - Dual port memory plus time

     DS1994
	    - 4k plus time iButton

     DS1427
	    - Time iButton

SYNOPSIS
     Real time clock, 4kbit memory. 3-wire interface, too.

     04.XXXXXXXXXXXX / alarm | auto | cycle | date | delay | interval | memory |
     pages/page.[0-15|ALL]  |  readonly/[memory|clock|cycle|interval] | memory |
     pages/page.[0-15|ALL] | readonly/[memory|clock|cycle|interval] | running  |
     set_alarm | start | trigger/[cycle,date,interval,udate,uinterval] | udate |
     uinterval	| address | crc8 | id | locator | r_address | r_id | r_locator |
     type

     84.XXXXXXXXXXXX / alarm | auto | cycle | date | delay | interval | memory |
     pages/page.[0-15|ALL] | readonly/[memory|clock|cycle|interval] | running  |
     set_alarm | start | trigger/[cycle,date,interval,udate,uinterval] | udate |
     uinterval | address | crc8 | id | present | type

FAMILY CODE
     04     DS2404 DS1994

     84     DS1427 DS2404S

SPECIAL PROPERTIES
   alarm
     read-write, unsigned integer (0-111)
     Alarm  state of the DS2404 (3) triggered by time or counter events. Reading
     the alarm state clears the alarm.
     The alarm value is of the form CIR, where:

     C	    cycle counter alarm
	    0 no
	    1 yes

     I	    interval timer alarm
	    0 no
	    1 yes

     R	    real-time clock alarm
	    0 no
	    1 yes

   auto
     read-write, yes-no
     Flag for mode of interval counter operation. 0=manual 1=auto
     See the datasheet for details.

   date
     read-write, ascii
     26 character date representation of the udate value.  Increments  once  per
     second while running
     Actual internal representation has higher precision.
     Cannot be altered if readonly/clock is set.
     Setting date to a null string will put the current system time.
     Accepted date formats are:
       Sat[urday] March 12 12:23:59 2001
       Apr[il] 4 9:34:56 2002
       3/23/04 23:34:57
       current locale setting (your system's format)

   delay
     read-write, yes-no
     Flag for adding a delay to cycle counter. 0=short 1-long
     See the datasheet under "IDEL" for details.

   interval
     read-write, date
     Interval  timer value, represented as a date string. More typically will be
     used as uinterval to read the actual elapsed seconds.

   memory
     read-write, binary
     512 bytes of memory. The readonly/memory flag prevents further change.

   pages/page.0 ... pages/page.15 pages/page.ALL
     read-write, yes-no
     Memory is split into 16 pages of 32 bytes each.  The  readonly/memory  flag
     prevents  further	change.   ALL is an aggregate of the pages. Each page is
     accessed sequentially.

   readonly/[memory|clock|interval|cycle]
     read-write, yes-no
     Permanently protect part of the chip's function from alteration.

     readonly/memory
	    page.X and memory

     readonly/clock
	    date and udate

     readonly/interval
	    interval

     readonly/cycle
	    cycle

   running
     read-write, yes-no
     State of the clock. 0=off 1=running.

   set_alarm
     read-write, unsigned integer (0-111)
     Which of the alarm triggers are enabled in the DS2404 (3)
     The set_alarm value is of the form CIR, where:

     C	    cycle counter alarm
	    0 no
	    1 yes

     I	    interval timer alarm
	    0 no
	    1 yes

     R	    real-time clock alarm
	    0 no
	    1 yes

   start
     read-write, yes-no
     Flag for starting the interval counter  operation	if  not  in  auto  mode.
     0=stop 1=start
     See the datasheet for details.

   trigger/[cycle,date,interval,udate,uinterval]
     read-write,varies
     Target  value  that  will	trigger the alarm if the corresponding set_alarm
     field is set.
     The format is the same as the similarly named field (i.e.	date  for  trig-
     ger/date )

   udate
     read-write, unsigned integer
     Time represented as a number.  udate increments once per second, while run-
     ning is on.
     Usually set to unix time standard: number of seconds since Jan 1, 1970. The
     date field will be the unix representation of udate and setting either will
     change the other.

   uinterval
     read-write, unsigned interval
     Similar to the udate field, except corresponds to the interval value.

STANDARD PROPERTIES
   address
   r_address
     read-only, ascii
     The  entire 64-bit unique ID. Given as upper case hexadecimal digits (0-9A-
     F).
     address starts with the family code
     r address is the address in reverse order, which is often used in other ap-
     plications and labeling.

   crc8
     read-only, ascii
     The 8-bit error correction portion. Uses cyclic redundancy check.	Computed
     from  the	preceding  56  bits of the unique ID number. Given as upper case
     hexadecimal digits (0-9A-F).

   family
     read-only, ascii
     The 8-bit family code. Unique to each type of device. Given as  upper  case
     hexadecimal digits (0-9A-F).

   id
   r_id
     read-only, ascii
     The  48-bit  middle  portion  of the unique ID number. Does not include the
     family code or CRC. Given as upper case hexadecimal digits (0-9A-F).
     r id is the id in reverse order, which is often used in other  applications
     and labeling.

   locator
   r_locator
     read-only, ascii
     Uses  an extension of the 1-wire design from iButtonLink company that asso-
     ciated 1-wire physical connections with a unique 1-wire code. If  the  con-
     nection is behind a Link Locator the locator will show a unique 8-byte num-
     ber (16 character hexadecimal) starting with family code FE.
     If  no Link Locator is between the device and the master, the locator field
     will be all FF.
     r locator is the locator in reverse order.

   present (DEPRECATED)
     read-only, yes-no
     Is the device currently present on the 1-wire bus?

   type
     read-only, ascii
     Part name assigned by  Dallas  Semi.  E.g.   DS2401  Alternative  packaging
     (iButton vs chip) will not be distiguished.

ALARMS
     None implemented.

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-connec-
     tor 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, temper-
     ature,  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  indi-
     vidually 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 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.

     Details  of  the individual slave or master design are hidden behind a con-
     sistent interface. The goal is to provide an easy set of tools for a  soft-
     ware  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	correct-
     ness rather than speed.

   DS1427 DS1994 DS2404 DS2404S
     The  DS1427  (3),	DS1994 (3), DS2404 (3), and DS2404S (3) family of 1-wire
     devices includes clock functions, with timers, memory, counters and alarms.
     It is possible to write-protect regians of memory. Uses include software or
     hardware timing and control.

   Chips
     Both the DS2404 (3) and DS2404S (3)  have	1-wire	and  3-wire  interfaces,
     which  might  be useful for transferring data between the 2 buses. They act
     as a passive slave to both buses. The DS2404 (3) and DS2404S (3) require an
     external source of power and an external crystal. They also offer	a  reset
     and 1HZ clock pin.

   iButtons
     Both  the DS1427 and DS1994 offer the memory, alarms, and clock function in
     iButton format. Because the iButton is a complete sealed  package,  battery
     and crystal are internal. Everything is access via the 1-wire interface.

ADDRESSING
     All  1-wire  devices are factory assigned a unique 64-bit address. This ad-
     dress is of the form:

     Family Code
	    8 bits

     Address
	    48 bits

     CRC    8 bits

     Addressing under OWFS is in hexadecimal, of form:

	    01.123456789ABC

     where 01 is an example 8-bit family code, and 12345678ABC is an example  48
     bit address.

     The dot is optional, and the CRC code can included. If included, it must be
     correct.

DATASHEET
     http://pdfserv.maxim-ic.com/en/ds/DS2404.pdf
     http://pdfserv.maxim-ic.com/en/ds/DS2404S-C01.pdf
     http://pdfserv.maxim-ic.com/en/ds/DS1994.pdf
     http://pdfserv.maxim-ic.com/en/ds/DS1427.pdf

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) Infer-
     noEmbedded (3)

   Temperature
     DS1822 (3) DS1825 (3) DS1820 (3) DS18B20 (3) DS18S20 (3) DS1920 (3)  DS1921
     (3) DS1821 (3) DS28EA00 (3) DS28E04 (3) EDS0064 (3) EDS0065 (3) EDS0066 (3)
     EDS0067 (3) EDS0068 (3) EDS0071 (3) EDS0072 (3) MAX31826 (3)

   Humidity
     DS1922 (3) DS2438 (3) EDS0065 (3) EDS0068 (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 (3) EDS0066 (3) EDS0068 (3)

   Moisture
     EEEF (3) DS2438 (3)

AVAILABILITY
     http://www.owfs.org

AUTHOR
     Paul Alfille (paul.alfille@gmail.com)

OWFS Manpage			      2006			       DS2404(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=DS2404&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>

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