Re: Re: Serial protocol questions

["DynamoBen" <ben@xxxxxxxxxxx>]

BTW 1/8 fuses on the data line is always a good idea.
----- Original Message -----
From: "DynamoBen" <ben@xxxxxxx>
To: <ukha_xpl@xxxxxxx>
Sent: Monday, January 24, 2005 2:53 PM
Subject: Re: [ukha_xpl] Re: Serial protocol questions


>
> RS485 hubs are super easy to build. In fact you could mock one up on a
> breadboard in under 30mins. (They are generally called opto splitters)
>
> Parts Needed:
> Several 75176 chips (less than 32)
> Several 6N137 chips (this is for opto isloation)
>
> Data path is RS485-->75176 Input-->6N137
>
> Then this would be repeated for the outputs. Don't for get to tie TX
to
> RX.
>
> This make sense?
>
>
> ----- Original Message -----
> From: "Frank Mc Alinden" <fmcalind@xxxxxxx>
> To: <ukha_xpl@xxxxxxx>
> Sent: Monday, January 24, 2005 2:46 PM
> Subject: Re: [ukha_xpl] Re: Serial protocol questions
>
>
>>
>> Hi Guys
>>        Have to agree with  Lehane that its better to have lots of
small
>> devices than to make one that does all ...........
>> Would that mean then a rs485 hub would be required so that it
could be
>> star
>> wired ??? anybody did a rs485 hub before ????
>>
>> Allowing the network to run at different baud rates is a good idea
>> ,anything
>> i have done is 9600 , although i dont think 19200 would be out of
the
>> question for most pics...??
>>
>> The important thing to get this project going i think is to get 
started
>> on
>> the master device....
>>
>> Neil  do you have any current hardware to develope a Master on
????
>>
>>> 2) Presumably the host software will do the device/instance
id->node
>>> number conversion and the device/instance config? - Don't know
what this
>> is
>>> yet ???
>>
>> Each node has a name / id and its configurable , so when you put a
new
>> device on the network it will sent out regular requests
"please configure
>> me" known as config heartbeats....The master should pick up
this message
>> and
>> pass it on to the xPL network....In xPL Manager under xPL
>> devices,subfolder
>> awaiting configuration the device should be listed clicking on it
then
>> allows you to configure....The config info would get send to the
Master
>> which passes it on to the new unit which would reconfigure its
self and
>> immediately send out a regular heartbeat.....
>> Hope that makes sense ??
>>
>> Frank
>>
>>
>> ----- Original Message -----
>> From: "Neil Wrightson" <neilw@xxxxxxx>
>> To: <ukha_xpl@xxxxxxx>
>> Sent: Tuesday, January 25, 2005 7:21 AM
>> Subject: RE: [ukha_xpl] Re: Serial protocol questions
>>
>>
>>>
>>> Hi Lehane,
>>>
>>> 1) I made reference to the compiler I use purely because it is
a good
>>> compiler. Each different type of slave could be a completely
different
>> micro
>>> and language - assembler, C, Basic Pascal etc etc. The main
thing is
>>> that
>>> handles its own task and interfaces to the required 485
network
>>> protocol.
>>>
>>> 2) Presumably the host software will do the device/instance
id->node
>>> number conversion and the device/instance config? - Don't know
what this
>> is
>>> yet ???
>>>
>>> 3) "Mmm!
>>> I'd caution against making the devices too complex. Better
have 10
>>> types (smaller/cheaper) than 1 do-everything and they are
likely to
>>> see the light of day faster. You can always put two/three/four
in one
>>> box." - Exactly
>>>
>>>
>>> 4) "So I'd go for:
>>> 1 n-way DC input (maybe analogue) variations can include
on/off,
>>> momentary, dimmer action, etc.
>>> 2 n-way DC output (maybe PWM on some for LED's) variations -
opto,
>>> SSR, etc
>>> 3 LCD display driver
>>> 4 RFID (...and RFID to me is EPC/ISO 18000)
>>> 5 Universal IR (UIRT on 485)
>>> 6 Dallas touch and/or one wire sensors
>>> 7 MSR (Track 1/2/3)
>>> 8 Bar Code Reader (UPC/EAN/ITF/Code 39)
>>> 9 Analog input/output (0-5/10V)
>>> 10 .... "
>>>
>>> A) I was thinking of analogue inputs for switches etc, adds
additional
>>> security to remote switches I.e. window reed switches or PIR's
>>>
>>> B) What is "EPC/ISO 18000"
>>>
>>> C) What is MSR (Track 1/2/3)
>>>
>>>
>>>
>>> 5) "Agree on the power to the unit, although 12-15V maybe
sufficient as
>>> the power consumption is going to be pretty low on most.
>>> Not sure about the audio..I think that belongs on Ethernet in
the
>>> digital domain. I guess you're looking at voice/audio feedback
but
>>> would you want output from every device? Or would you command
each
>>> amp on? "
>>> RS485 Cabling is generally as per the old coax 10base2, one
long line
>>> with
>>> terminators on either end.
>>> With up to 32 devices on this line, that means 64 connections,
each with
>>> it's own voltage drop. The higher you can have the supply
voltage the
>>> less
>>> current in the supply lines the less voltage drop on the cable
and the
>> less
>>> impact of voltage drops on the network connectors.
>>> A lot of filed devices requires 12VDC so you would at least
have to add
>> 50%
>>> i.e. 18VDC for the interconnecting power supply. I know of
lots of off
>>> the
>>> shelf 24VDC supplies out there. But, I think that as long as
we design
>>> the
>>> system so that it can handle from 12..24VDC, we can leave it
up to the
>>> individual.
>>>
>>> 6) As far as the audio goes, my intention was that we use the
speaker
>>> out
>> of
>>> the HA pc. Nothing fancy.
>>> I see this as been a separate plug in add on board to the main
slave
>>> terminal with a small amp etc.
>>>
>>>
>>> 7) RS485 Comms Speed
>>> For each slave the master must Tx a message and then Rx a
message. 32
>> Slaves
>>> times * 2 * Packet size of say ten characters = 640 bytes. At
9600 baud
>> this
>>> would mean dial around would take 1.5 seconds. In reality this
would be
>>> somewhat longer with internal delays etc. Hence the reason
that I
>> suggested
>>> 38400 baud. I know basic chips may have issues with this.
Again perhaps
>> user
>>> definable 9600/38400.
>>> Build the network to your own needs.
>>>
>>>
>>> Neil.
>>>
>>>
>>>
>>>
>>>
>>> written in a completely differant language or
>>>
>>>
>>> Regards,
>>>
>>> Neil Wrightson.
>>> -----Original Message-----
>>> From: g8kmh [mailto:lehane@xxxxxxx]
>>> Sent: Tuesday, 25 January 2005 12:46 AM
>>> To: ukha_xpl@xxxxxxx
>>> Subject: [ukha_xpl] Re: Serial protocol questions
>>>
>>>
>>>
>>>
>>> I've dropped my response in below.
>>>
>>> Lehane
>>>
>>> --- In ukha_xpl@xxxxxxx, "Neil Wrightson"
<neilw@n...> wrote:
>>> > Hi Guys,
>>> >
>>> > 1) I'm all for a combined project.
>>> >
>>> > 2) I don't want to start another mine is better than
yours
>>> discussion, but,
>>> > I use AVR's :) I have a great compiler AVRCo with true
multitasking
>>> etc
>>>
>>> To some extent it is irrelevent to most end-users. Few are
going to
>>> change code, some will want prog'ed devices and most a kit (or
at
>>> least PCB and CPU).
>>>
>>> The protocol outline is doable across a wide range of devices,
indeed
>>> it needs to be interoperable.
>>>
>>> >
>>> > 3) I think that a dedicated 485 network controller will
be
>>> required. I think
>>> > the 485 comms will probably run about 38400 baud.
>>> >     A 16MHz AVR will happily look after this.
>>> >     The network controller will pass and receive all
state changes
>>> to the PC
>>> > as well as heart beats for each device.
>>> >     Comms to the PC could be 9600.
>>> >
>>>
>>> A separate controller has some advantages of redundancy and
>>> interfacing with Win* or *nix.
>>>
>>> With xPL not on the wire then heartbeats can be different
internally
>>> to externally.
>>>
>>> Presumably the host software will do the device/instance
id->node
>>> number conversion and the device/instance config?
>>>
>>>
>>> > 4) I envisage that there be at least two types of room
controllers
>>> (Perhaps
>>> > we should start by settling on some names for these
things)
>>> >     a) Bedroom/kitchen/Living area Controller wish list
>>> >         Display,
>>> >         Personnel Switches for lights, sound muting etc,
>>> >         Data entry method, Set room alarm clock time etc
Sleep time
>>> for
>>> > lighting etc
>>> >         IR Transmitter, Turn telly off when I fall asleep
in bed,
>>> turn
>>> > ceiling fan off etc etc
>>> >         Personal ID method
>>> >         Sound
>>> >         Movement sensor interface
>>> >         Switch inputs for door & window reed switches
>>> >
>>> >     b) Basic room as in garage/toilet/bathroom wish list
>>> >         Personnel Switches for lights etc,
>>> >         Sound
>>> >         Movement sensor interface
>>> >         Switch inputs for door & window reed switches
>>> >         Note - This is to be a cheaper version, no
display only
>>> beeper for
>>> > sound alerts, maybe a IR receiver for configuration ??
>>> >
>>> > Hardware Solutions for above
>>> >         Display,
>>> > 16*2 LCD with LED backlight OR maybe a small graphic LCD,
could
>>> display
>>> > small icons for
>>> >
>>> > you have email, voice messages, phone callers etc.
>>> >         Personnel Switches for lights
>>> etc,                             2..4
>>> > Tactile switches I.e. small PCB mount
>>> >         Light Control
>>> > either 240V relay or triac, triac allows dimming, great
for those
>>> wee stops
>>> > in the night
>>> >         Data entry method,
>>> > Universal TV remote. I can currently decode Sony or RC5
signals
>>> >         IR Transmitter
>>> > IR led on controller as well as capability to add an
external IR
>>> led else
>>> > where in the room
>>> >
>>> > for better coverage if needed, I.e. Living room with
external LED
>>> for Stereo
>>> > etc.
>>> >         Personal ID method
>>> > Dallas 1 wire ibutton, A lot cheaper & smaller than
RFID!
>>> >         Sound
>>> > 2 Types, 1) Standard beeper. 2) Optional 1W speaker with
sound
>>> relaying from
>>> > controller Pc
>>> >
>>> > Probably a separate optional PCB.
>>> >         Movement sensor
>>> interface                                    As
>>> > suggested either a integrated unit actually on the
controller or a
>>> separate
>>> > security PIR
>>> >         Switch inputs for door & window reed switches
>>> Standard style
>>> > of inputs on a micro 5..12V tolerant.
>>> >
>>> >         Power Supply and Signal
>>> >             I suggest that we use CAT5
>>> >             Power - 2 Pairs 1 pair for 0V and one pair
for +24V.
>>> >             Comms Signal  - 1 Pair
>>> >             Audio from PC - 1 Pair
>>> >             If we try to use the standard pin outs for
power over
>>> Ethernet
>>> > and data signals, nothing will be damaged if
>>> >             a wrong device is plugged in somewhere.
>>> >             Although, I did see these devices as being
panel
>>> mounted on the
>>> > walls.
>>> >
>>> Mmm!
>>> I'd caution against making the devices too complex. Better
have 10
>>> types (smaller/cheaper) than 1 do-everything and they are
likely to
>>> see the light of day faster. You can always put two/three/four
in one
>>> box.
>>> So I'd go for:
>>> 1 n-way DC input (maybe analog) variations can include on/off,
>>> momentary, dimmer action, etc.
>>> 2 n-way DC output (maybe PWM on some for LED's) variations -
opto,
>>> SSR, etc
>>> 3 LCD display driver
>>> 4 RFID (...and RFID to me is EPC/ISO 18000)
>>> 5 Universal IR (UIRT on 485)
>>> 6 Dallas touch and/or one wire sensors
>>> 7 MSR (Track 1/2/3)
>>> 8 Bar Code Reader (UPC/EAN/ITF/Code 39)
>>> 9 Analog input/output (0-5/10V)
>>> 10 ....
>>>
>>> Agree on the power to the unit, although 12-15V maybe
sufficient as
>>> the power consumption is going to be pretty low on most.
>>> Not sure about the audio..I think that belongs on Ethernet in
the
>>> digital domain. I guess you're looking at voice/audio feedback
but
>>> would you want output from every device? Or would you command
each
>>> amp on?
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> xPL Links: http://www.xplproject.org.uk <http://www.xplproject.org.uk>
>>> http://www.xplhal.com
<http://www.xplhal.com>  http://www.xpl.myby.co.uk
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>>
>>
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>> http://www.xpl.myby.co.uk
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>
>
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