DS2409(3)

1DS2409(3)                    One-Wire File System                    DS2409(3)
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NAME

6       DS2409 - MicroLAN Coupler
7

SYNOPSIS

9       1-wire network branch controller.
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11       1F  [.]XXXXXXXXXXXX[XX][/[ aux | branch.[0|1|ALL|BYTE] | control | dis‐
12       charge   |    event.[0|1|ALL|BYTE]    |    clearevent    |    main    |
13       sensed.[0|1|ALL|BYTE]  |  address  |  crc8 | id | locator | r_address |
14       r_id | r_locator | type ]]
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FAMILY CODE

17       1F
18

SPECIAL PROPERTIES

20   aux
21       directory
22       This is the aux branch of the DS2409 network branch. It  is  implicitly
23       accessed (via the aux smart-on command) when it is listed or devices on
24       this branch are addressed.
25
26   branch.0 branch.1 branch.ALL branch.BYTE
27       read-write, yes-no
28       Writing a value of 1 to the branch properties  explicitly  selects  the
29       meant branch ( 0=main or 1=aux ). Writing 0 deselects the branch.  This
30       is an addition to the directory branch selection  scheme  available  by
31       simply  accessing  the  main and aux directories. Both ways to select a
32       branch coexist nicely but the latest scheme used wins.   Attempting  to
33       select  both  branches, either by setting both bits at the same time or
34       subsequently, fails.  Clearing both branch selection  bits,  either  by
35       clearing  both  bits at the same time or subsequently, resets the event
36       flags inside the DS2409 as a side effect.  Reading the  branch  proper‐
37       ties returns which branch (if any) is connected to the master bus.
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39       After  using  the  directory branch selection scheme, both branches are
40       deselected automatically.
41
42       ALL is an aggregate of the properties, comma separated. It is an atomic
43       operation.
44       BYTE is an aggregate of the branches as a byte, main is bit 0. It is an
45       atomic operation.
46
47   control
48       read-write, unsigned integer
49       Setting of the PIO control pin. There are 4 possible settings:
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51       0      Unconditionally off (non-conducting)
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53       1      Unconditionally on (conducting)
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55       2      Auto on when main branch switched in
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57       3      Auto on when aux branch switched in
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59   discharge
60       write-only, yes-no
61       Writing a non-zero value to this property will electrically reset  both
62       the main and auxiliary branches of the 1-wire bus by dropping power for
63       100 milliseconds. All devices on those  branches  will  lose  parasitic
64       power  and  reset  to  power-up  defaults. As a side effect, both event
65       flags and thus, the alarm state, are cleared, too.
66
67   event.0 event.1 event.ALL event.BYTE
68       read-only, yes-no
69       Has the event flag for the branch been triggered? A  negative  edge  on
70       the  disconnected  branch  (  0=main  or 1=aux ) sets the flag. This is
71       achieved by e.g. connecting an iButton to the branch. Value returned is
72       1 (yes) or 0 (no).
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74       After accessing the main or aux directory, both branches are deselected
75       automatically and thus, the event flags and alarm state are cleared.
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77       ALL is an aggregate of the properties, comma separated. It is an atomic
78       operation.
79       BYTE is an aggregate of the branches as a byte, main is bit 0. It is an
80       atomic operation.
81
82   clearevent
83       write-only, yes-no
84       Writing a non-zero value to this property will reset both  event  flags
85       and thus, clear the alarm state, too.
86
87   main
88       directory
89       This  is the main branch of the DS2409 network branch. It is implicitly
90       accessed (via the main smart-on command) when it is listed  or  devices
91       on this branch are addressed.
92
93   sensed.0 sensed.1 sensed.ALL sensed.BYTE
94       read-only, yes-no
95       Voltage  sensed  at the 0=main or 1=aux branch pin. Valid only when the
96       branch is switched out. Value returned is 0 (low) or 1 (high).
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98       ALL is an aggregate of the properties, comma separated. It is an atomic
99       operation.
100       BYTE is an aggregate of the branches as a byte, main is bit 0. It is an
101       atomic operation.
102

STANDARD PROPERTIES

104   address
105   r_address
106       read-only, ascii
107       The entire 64-bit unique ID. Given as  upper  case  hexidecimal  digits
108       (0-9A-F).
109       address starts with the family code
110       r address is the address in reverse order, which is often used in other
111       applications and labeling.
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113   crc8
114       read-only, ascii
115       The 8-bit error correction portion. Uses cyclic redundancy check.  Com‐
116       puted  from  the  preceding  56  bits of the unique ID number. Given as
117       upper case hexadecimal digits (0-9A-F).
118
119   family
120       read-only, ascii
121       The 8-bit family code. Unique to each type of device.  Given  as  upper
122       case hexadecimal digits (0-9A-F).
123
124   id
125   r_id
126       read-only, ascii
127       The 48-bit middle portion of the unique ID number. Does not include the
128       family code or CRC. Given as upper case hexadecimal digits (0-9A-F).
129       r id is the id in reverse order, which is often used in other  applica‐
130       tions and labeling.
131
132   locator
133   r_locator
134       read-only, ascii
135       Uses  an  extension  of the 1-wire design from iButtonLink company that
136       associated 1-wire physical connections with a unique  1-wire  code.  If
137       the  connection is behind a Link Locator the locator will show a unique
138       8-byte number (16 character hexadecimal) starting with family code FE.
139       If no Link Locator is between the device and the  master,  the  locator
140       field will be all FF.
141       r locator is the locator in reverse order.
142
143   present (DEPRECATED)
144       read-only, yes-no
145       Is the device currently present on the 1-wire bus?
146
147   type
148       read-only, ascii
149       Part  name  assigned by Dallas Semi. E.g.  DS2401 Alternative packaging
150       (iButton vs chip) will not be distiguished.
151

ALARMS

153       The DS2409 will respond to a conditional search if the main event  flag
154       is set.
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DESCRIPTION

157   1-Wire
158       1-wire is a wiring protocol and series of devices designed and manufac‐
159       tured by Dallas Semiconductor, Inc. The bus is  a  low-power  low-speed
160       low-connector scheme where the data line can also provide power.
161
162       Each  device  is  uniquely and unalterably numbered during manufacture.
163       There are a wide variety of devices, including memory, sensors  (humid‐
164       ity, temperature, voltage, contact, current), switches, timers and data
165       loggers. More complex devices (like thermocouple sensors) can be  built
166       with  these  basic  devices.  There  are  also 1-wire devices that have
167       encryption included.
168
169       The 1-wire scheme uses a single bus master and multiple slaves  on  the
170       same  wire.  The bus master initiates all communication. The slaves can
171       be individually discovered and addressed using their unique ID.
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173       Bus masters come in a variety of configurations including serial,  par‐
174       allel, i2c, network or USB adapters.
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176   OWFS design
177       OWFS  is  a  suite of programs that designed to make the 1-wire bus and
178       its devices easily accessible. The underlying principle is to create  a
179       virtual  filesystem,  with  the  unique ID being the directory, and the
180       individual properties of the device are  represented  as  simple  files
181       that can be read and written.
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183       Details  of  the  individual slave or master design are hidden behind a
184       consistent interface. The goal is to provide an easy set of tools for a
185       software  designer  to create monitoring or control applications. There
186       are some performance enhancements in the implementation, including data
187       caching, parallel access to bus masters, and aggregation of device com‐
188       munication. Still the fundamental goal has been ease of use,  flexibil‐
189       ity and correctness rather than speed.
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191   DS2409
192       The  DS2409 (3) allows complex 1-wire network topology. Each branch has
193       it's power preserved, even when isolated from the  master.  A  separate
194       PIO  pin  can  be  configured  to  show branch switching, or controlled
195       explicitly.
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ADDRESSING

198       All 1-wire devices are factory assigned a unique 64-bit  address.  This
199       address is of the form:
200
201       Family Code
202              8 bits
203
204       Address
205              48 bits
206
207       CRC    8 bits
208
209       Addressing under OWFS is in hexadecimal, of form:
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211              01.123456789ABC
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213       where 01 is an example 8-bit family code, and 12345678ABC is an example
214       48 bit address.
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216       The dot is optional, and the CRC code can  included.  If  included,  it
217       must be correct.
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DATASHEET

220       http://pdfserv.maxim-ic.com/en/ds/DS2409.pdf
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AVAILABILITY

283       http://www.owfs.org
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AUTHOR

286       Paul Alfille (paul.alfille@gmail.com)
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290OWFS Manpage                         2003                            DS2409(3)