> Il 19/04/2016 11:05, raimond.dragomir@gmail.com ha scritto:
> > [...]
>> ST7540
>> ST7538
>> ST7570
>> ST7580
>> ST7590
>
> Those chips are for powerline (mains AC). Could they be used with DC low
> voltage (12-24V) too?
There is an application note from ST that shows how to use their PLC
modem in DC powered bus applications.
http://www2.st.com/content/ccc/resource/technical/document/design_note/e5/92/04/77/ad/f4/4e/ed/DM00061910.pdf/files/DM00061910.pdf/jcr:content/translations/en.DM00061910.pdf
Other manufacturers make PLC modems that should work in DC bus. For
example ON Semiconductor (NCN49599), NXP (TDA5051A, up to 1200bps),
Cypress (CY8CPLC10), TI (www.ti.com/tool/24vdcplcevm).
There is an israelian company that sells a proprietary solutions:
http://yamar.com
Did someone use one of those solution? Any suggestions for a low-cost
consumer applications?
What I need is to have a DC powered (10-30Vdc) half-duplex multi-master
proprietary bus with a low bit-rate (at least 9600bps). The number of
nodes will be 50-100 at maximum.
Reply by pozz●April 20, 20162016-04-20
Il 18/04/2016 12:12, pozz ha scritto:
> There are many commercial solutions for home-automation systems that are
> based on a two wires bus both for bidirectional data and for powering
> the modules. The number of connected modules could be high, 100 or more.
>
> What is the technology of those kind of buses? Are they simple
> half-duplex RS485? In this case, how the power can be distributed on the
> same wires of data? Is the protocol master/slave? In this case, the time
> to poll all the modules could be some seconds and the reaction of user
> commands is very bad.
>
> Or are there other solutions?
Il 19/04/2016 11:05, raimond.dragomir@gmail.com ha scritto:
> [...]
> ST7540
> ST7538
> ST7570
> ST7580
> ST7590
Those chips are for powerline (mains AC). Could they be used with DC low
voltage (12-24V) too?
Reply by pozz●April 20, 20162016-04-20
Il 18/04/2016 12:12, pozz ha scritto:
> There are many commercial solutions for home-automation systems that are
> based on a two wires bus both for bidirectional data and for powering
> the modules. The number of connected modules could be high, 100 or more.
>
> What is the technology of those kind of buses? Are they simple
> half-duplex RS485? In this case, how the power can be distributed on the
> same wires of data? Is the protocol master/slave? In this case, the time
> to poll all the modules could be some seconds and the reaction of user
> commands is very bad.
>
> Or are there other solutions?
One technology already used in home automation systems is KNX on twisted
pair, what is called KNX TP1-256.
You have a two-wires bus where DC voltage (about 30Vdc) and data
(9600bps) are mixed together.
On a KNX bus line you must have a specific KNX bus power supply that
injects DC voltage for powering modules on the bus.
When one node wants to transmit zero, it puts a load on the bus for
35us. The load should sink as much current as possible to have a
decrease of 6-9V on the DC voltage on the bus.
The power supply integrates a choke that should make the magic.
There are some ready-to-use chips that integrates many useful features:
bus coupling, DC/DC, bit decoding and so on. For example, ON
semiconductors makes: NCN5110, NCN5121 and NCN5130.
Reply by pozz●April 20, 20162016-04-20
Il 19/04/2016 16:09, Grant Edwards ha scritto:
> On 2016-04-19, pozz <pozzugno@gmail.com> wrote:
>> Il 18/04/2016 16:28, Grant Edwards ha scritto:
>>> On 2016-04-18, pozz <pozzugno@gmail.com> wrote:
>>>
>>>> There are many commercial solutions for home-automation systems that are
>>>> based on a two wires bus both for bidirectional data and for powering
>>>> the modules.
>>>
>>> There are a few. HART, Foundation Fieldbus H1, Profibus MBP, etc.
>>
>> They seem all industrial solutions where the cost is higher than
>> consumer market.
>
> Nobody said anything about the consumer market.
Home automation is consumer market.
>> HART seems a master/slave protocol,
>
> Mostly, but not entirely
>
>> it can't be used for building automation applications, where you
>> need a fast response to a push button press.
>
> And now we're talking about building automation?
Yes, my original post was about "home automation".
>>>> What is the technology of those kind of buses? Are they simple
>>>> half-duplex RS485?
>>>
>>> No. Typically you AC-couple manchester-encoded (or FSK) data onto the
>>> wire-pair. You also have to add a filter to your power-supply to make
>>> it high-impedance at the comm frequencies.
>>
>> Are there any ready-to-use cheap solutions? I don't think building
>> automation products are based on complex and big electronic boards.
>
> Perhaps it would have helped if we knew you looking for cheap,
> consumer-market, building automation technology. Are you?
I'm curious about commercial (already on the market) technologies that
allow to create a bus with only two-wires for power and data.
I'm interested mainly in consumer medium/low price products.
> Are you looking for mains powerline communication?
Is powerline used only with AC mains (230/110Vac)? Home automation
systems usually have small devices that are DC powered.
Reply by Grant Edwards●April 19, 20162016-04-19
On 2016-04-19, pozz <pozzugno@gmail.com> wrote:
> Il 18/04/2016 16:28, Grant Edwards ha scritto:
>> On 2016-04-18, pozz <pozzugno@gmail.com> wrote:
>>
>>> There are many commercial solutions for home-automation systems that are
>>> based on a two wires bus both for bidirectional data and for powering
>>> the modules.
>>
>> There are a few. HART, Foundation Fieldbus H1, Profibus MBP, etc.
>
> They seem all industrial solutions where the cost is higher than
> consumer market.
Nobody said anything about the consumer market.
> HART seems a master/slave protocol,
Mostly, but not entirely
> it can't be used for building automation applications, where you
> need a fast response to a push button press.
And now we're talking about building automation?
>>> What is the technology of those kind of buses? Are they simple
>>> half-duplex RS485?
>>
>> No. Typically you AC-couple manchester-encoded (or FSK) data onto the
>> wire-pair. You also have to add a filter to your power-supply to make
>> it high-impedance at the comm frequencies.
>
> Are there any ready-to-use cheap solutions? I don't think building
> automation products are based on complex and big electronic boards.
Perhaps it would have helped if we knew you looking for cheap,
consumer-market, building automation technology. Are you?
Are you looking for mains powerline communication?
--
Grant Edwards grant.b.edwards Yow! ... I want FORTY-TWO
at TRYNEL FLOATATION SYSTEMS
gmail.com installed within SIX AND A
HALF HOURS!!!
Reply by ●April 19, 20162016-04-19
marți, 19 aprilie 2016, 11:47:00 UTC+3, pozz a scris:
> Il 18/04/2016 18:55, Tim Wescott ha scritto:
> > On Mon, 18 Apr 2016 12:12:45 +0200, pozz wrote:
> >
> >> There are many commercial solutions for home-automation systems that are
> >> based on a two wires bus both for bidirectional data and for powering
> >> the modules. The number of connected modules could be high, 100 or
> >> more.
> >>
> >> What is the technology of those kind of buses? Are they simple
> >> half-duplex RS485? In this case, how the power can be distributed on the
> >> same wires of data? Is the protocol master/slave? In this case, the time
> >> to poll all the modules could be some seconds and the reaction of user
> >> commands is very bad.
> >>
> >> Or are there other solutions?
> >
> > The general idea is that you use diplexers everywhere, to separately
> > couple DC and comms onto the same set of wires.
>
> Any ready-to-use chips or reference designs to suggest?
>
>
> > But -- there's a reason that wireless is popular.
ST7540
ST7538
ST7570
ST7580
ST7590
Mouser have them all
Reply by pozz●April 19, 20162016-04-19
Il 18/04/2016 18:55, Tim Wescott ha scritto:
> On Mon, 18 Apr 2016 12:12:45 +0200, pozz wrote:
>
>> There are many commercial solutions for home-automation systems that are
>> based on a two wires bus both for bidirectional data and for powering
>> the modules. The number of connected modules could be high, 100 or
>> more.
>>
>> What is the technology of those kind of buses? Are they simple
>> half-duplex RS485? In this case, how the power can be distributed on the
>> same wires of data? Is the protocol master/slave? In this case, the time
>> to poll all the modules could be some seconds and the reaction of user
>> commands is very bad.
>>
>> Or are there other solutions?
>
> The general idea is that you use diplexers everywhere, to separately
> couple DC and comms onto the same set of wires.
Any ready-to-use chips or reference designs to suggest?
> But -- there's a reason that wireless is popular.
Reply by pozz●April 19, 20162016-04-19
Il 19/04/2016 01:51, Pete ha scritto:
> Grant Edwards wrote:
>> On 2016-04-18, pozz <pozzugno@gmail.com> wrote:
>>
>>> There are many commercial solutions for home-automation systems that are
>>> based on a two wires bus both for bidirectional data and for powering
>>> the modules.
>>
>> There are a few. HART, Foundation Fieldbus H1, Profibus MBP, etc.
>>
>>> What is the technology of those kind of buses? Are they simple
>>> half-duplex RS485?
>>
>> No. Typically you AC-couple manchester-encoded (or FSK) data onto the
>> wire-pair. You also have to add a filter to your power-supply to make
>> it high-impedance at the comm frequencies.
>
> A proprietary system that I once worked with used a DC voltage for logic
> high and a somewhat lower DC voltage for logic low.
In this case, each module on the bus should be capable to inject a DC
voltage on the bus (and changes its value when transmitting). I don't
think it is a simple solution.
Do you remember the bitrate?
Reply by pozz●April 19, 20162016-04-19
Il 18/04/2016 16:28, Grant Edwards ha scritto:
> On 2016-04-18, pozz <pozzugno@gmail.com> wrote:
>
>> There are many commercial solutions for home-automation systems that are
>> based on a two wires bus both for bidirectional data and for powering
>> the modules.
>
> There are a few. HART, Foundation Fieldbus H1, Profibus MBP, etc.
They seem all industrial solutions where the cost is higher than
consumer market.
HART seems a master/slave protocol, it can't be used for building
automation applications, where you need a fast response to a push button
press.
>> What is the technology of those kind of buses? Are they simple
>> half-duplex RS485?
>
> No. Typically you AC-couple manchester-encoded (or FSK) data onto the
> wire-pair. You also have to add a filter to your power-supply to make
> it high-impedance at the comm frequencies.
Are there any ready-to-use cheap solutions? I don't think building
automation products are based on complex and big electronic boards.