Prenos napajeni a dat po dvoudratu

[Robo Baranka]

No "original" m-bus ho iste nepotesi paramatrami (trosku odlisne od 
navrhnutych 7+5):
The transfer of bits from master to slave is accomplished by means of 
voltage level shifts. A
logical "1" (Mark) corresponds to a nominal voltage of +36 V at the output 
of the bus driver
(repeater), which is a part of the master; when a logical "0" (Space) is 
sent, the repeater
reduces the bus voltage by 12 V to a nominal +24 V at its output.
Bits sent in the direction from slave to master are coded by modulating the 
current
consumption of the slave. A logical "1" is represented by a constant (versus 
voltage,
temperature and time) current of up to 1.5 mA, and a logical "0" (Space) by 
an increased
current drain requirement by the slave of additional 11-20 mA. The mark 
state current can be
used to power the interface and possibly the meter or sensor itself.
zdroj: www.m-bus.org
takze ked uz, tak modifikovat

mimochodom cpu s adc na snimanie prudu: 
http://www.m-bus.com/files/minimaster.tif

robo


----- Original Message ----- 
From: "Pavel Poucha" <p.poucha na papouch.com>
To: "'HW-news'" <hw-list na list.hw.cz>
Sent: Wednesday, December 14, 2011 4:27 PM
Subject: RE: Prenos napajeni a dat po dvoudratu


Tak pak asi nejlépe ten M-BUS, případně "vlastní M-BUS" postavený na jeho
principech.

S pozdravem
ing. Pavel Poucha
jednatel
pavel.poucha na papouch.com

Papouch s.r.o.
Strašnická 1a, 102 00 Praha 10
Tel. +420 267 314 267-8
Fax +420 267 314 269

Máte-li chuť, navštivte naše stránky http://www.papouch.com/


-----Original Message-----
From: hw-list-bounces na list.hw.cz [mailto:hw-list-bounces na list.hw.cz] On
Behalf Of Petr Simek
Sent: Wednesday, December 14, 2011 4:25 PM
To: HW-news
Subject: RE: Prenos napajeni a dat po dvoudratu

On Wed, 14 Dec 2011, Pavel Poucha wrote:

> Na frekvenční modulaci se dá použít mnoho řešení, příklad jednoduché
> hardwarové s NE555 či jinými integrovanými oscilátory. Ale stejně u
> teplotního čidla budete mít procesor, tak to už je jedno, jestli vyšle
> pulsy přes UART, nebo to "zapíská" - tedy frekvenčně namoduluje.

To je prave to co nechci - delat se kvuli tomu se softem na generovani a
vyhodnocovani nejake frekvencni komunikace. Chci se tim zabyvat na urovni
cteni a zapisu USART registru, stravit s tim co nejmin casu.
Zkratka - "chci si jen vlasy umyt a jit"

> ing. Pavel Poucha

*------------------------------------------------------------------------*
|                          Petr Simek   APS JU                           |
|                             psimek na jcu.cz                              |
*------------------------------------------------------------------------*

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