DS2409(3) manual page

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.

branch.0 branch.1.html branch.ALL branch.BYTE

read-only, yes-no
Is the branch ( 0=main or 1=aux ) currently connected to the master bus? Value returned is 1 (yes) or 0 (no). The DS2409 should not allow both to be on simultaneously.
ALL is an aggregate of the properties, comma separated. It is an atomic operation.
BYTE is an aggregate of the branches as a byte, A is bit 0.

control

read-write, unsigned integer
Setting of the PIO control pin. There are 4 possible settings:

Unconditionally off (non-conducting)

Unconditionally on (conducting)

Auto on when main branch switched in

Auto on when aux branch switched in

discharge

write-only, yes-no
Writing a non-zero value to this property will electrically reset both the main and auxillary 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.

event.0 event.1.html event.ALL event.BYTE

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. Value returned is 1 (yes) or 0 (no).
ALL is an aggregate of the properties, comma separated. It is an atomic operation.
BYTE is an aggregate of the branches as a byte, A is bit 0.

main

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.

sensed.0 sensed.1.html sensed.ALL sensed.BYTE

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, A is bit 0.

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 preceeding 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

read-only, yes-no
Is the device currently present on the 1-wire bus?
Note, this means that each hex byte (2 characters) is reversed, not the text string.

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 Semicondictor, Inc. The bus is a low-power low-speed low-connector scheme where the data line can also provide power.

Each device is uniquely unalterably numbered during manufacture. There is a wide variety of devices, including memory, sensors (humidity, temperature, voltage, contact, current), switches, timers, loggers, and more complex devices (like thermocouple sensors) can be built wit hte basic devices. There are also 1-wire devices that have encryption included.

The 1-wire bus is accessed via one of a number of serial, parallel or USB adapters.

OWFS design

OWFS is a suite of programs that fundementally 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 files.

There is optional data caching to improved performance, but possible confusion over stale data.

Ds2409

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.

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.

Name
Synopsis
Family Code
Special Properties

aux
branch.0 branch.1.html branch.ALL branch.BYTE
control
discharge
event.0 event.1.html event.ALL event.BYTE
main
sensed.0 sensed.1.html sensed.ALL sensed.BYTE

Standard Properties

address
r_address
crc8
family
id
r_id
locator
r_locator
present
type

Alarms
Description

1-Wire
OWFS design
Ds2409

Addressing
Datasheet
See Also

Programs
Language bindings
Clocks
ID
Memory
Switches
Temperature
Humidity
Voltage
Resistance
Multifunction
Counter
LCD Screen
Crypto

Availability
Author

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