Provided by: owfs-doc_2.8p15-1ubuntu4_all bug

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 trigger/date )

   udate
       read-write, unsigned integer
       Time represented as a number.  udate increments once per second, while running 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 hexidecimal digits (0-9A-F).
       address starts with the family code
       r  address  is the address in reverse order, which is often used in other applications 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 hexidecimal digits (0-9A-
       F).

   family
       read-only, ascii
       The 8-bit family code. Unique to each type of device.  Given  as  upper  case  hexidecimal
       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 hexidecimal 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  associated  1-wire
       physical connections with a unique 1-wire code. If the connection is behind a Link Locator
       the locator will show a unique 8-byte number  (16  character  hexidecimal)  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-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.

   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
       busses. 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 address  is  of  the
       form:

       Family Code
              8 bits

       Address
              48 bits

       CRC    8 bits

       Addressing under OWFS is in hexidecimal, 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)

   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)

   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 EDS0066 (3) EDS0068 (3)

AVAILABILITY

       http://www.owfs.org

AUTHOR

       Paul Alfille (paul.alfille@gmail.com)