DS2409 − MicroLAN Coupler
1-wire network branch controller.
1F [.]XXXXXXXXXXXX[XX][/[ aux | branch.[0|1|ALL|BYTE] | control | discharge | event.[0|1|ALL|BYTE] | clearevent | main | sensed.[0|1|ALL|BYTE] | ]]
1F
directory
This is the aux branch of the DS2409 network
branch. It is implicitly accessed (via the aux
smart-on command) when it is listed or devices on this
branch are addressed.
read-write,
yes-no
Writing a value of 1 to the branch properties
explicitly selects the meant branch ( 0=main or
1=aux ). Writing 0 deselects the branch. This
is an addition to the directory branch selection scheme
available by simply accessing the main and aux
directories. Both ways to select a branch coexist nicely but
the latest scheme used wins. Attempting to select both
branches, either by setting both bits at the same time or
subsequently, fails. Clearing both branch selection bits,
either by clearing both bits at the same time or
subsequently, resets the event flags inside the
DS2409 as a side effect. Reading the branch
properties returns which branch (if any) is connected to the
master bus.
After using the directory branch selection scheme, both branches are deselected automatically.
ALL is an
aggregate of the properties, comma separated. It is an
atomic operation.
BYTE is an aggregate of the branches as a byte,
main is bit 0. It is an atomic operation.
read-write,
unsigned integer
Setting of the PIO control pin. There are 4 possible
settings:
0 |
Unconditionally off (non-conducting) |
|||
1 |
Unconditionally on (conducting) |
|||
2 |
Auto on when main branch switched in |
|||
3 |
Auto on when aux branch switched in |
write-only,
yes-no
Writing a non-zero value to this property will electrically
reset both the main and auxiliary branches of the 1-wire bus
by dropping power for 100 milliseconds. All devices on those
branches will lose parasitic power and reset to power-up
defaults. As a side effect, both event flags and
thus, the alarm state, are cleared, too.
read-only,
yes-no
Has the event flag for the branch been triggered? A
negative edge on the disconnected branch ( 0=main or
1=aux ) sets the flag. This is achieved by e.g.
connecting an iButton to the branch. Value returned is 1
(yes) or 0 (no).
After accessing the main or aux directory, both branches are deselected automatically and thus, the event flags and alarm state are cleared.
ALL is an
aggregate of the properties, comma separated. It is an
atomic operation.
BYTE is an aggregate of the branches as a byte,
main is bit 0. It is an atomic operation.
write-only,
yes-no
Writing a non-zero value to this property will reset both
event flags and thus, clear the alarm state, too.
directory
This is the main branch of the DS2409 network
branch. It is implicitly accessed (via the main
smart-on command) when it is listed or devices on this
branch are addressed.
read-only,
yes-no
Voltage sensed at the 0=main or 1=aux branch
pin. Valid only when the branch is switched out. Value
returned is 0 (low) or 1 (high).
ALL is an
aggregate of the properties, comma separated. It is an
atomic operation.
BYTE is an aggregate of the branches as a byte,
main is bit 0. It is an atomic operation.
The DS2409 will respond to a conditional search if the main event flag is set.
The DS2409 (3) allows complex 1-wire network topology. Each branch has it’s power preserved, even when isolated from the master. A separate PIO pin can be configured to show branch switching, or controlled explicitly.
http://pdfserv.maxim-ic.com/en/ds/DS2409.pdf
http://www.owfs.org
Paul Alfille ([email protected])