Re: Re: Serial protocol questions

["Frank Mc Alinden" <fmcalind@xxxxxxxxxxxxxx>]

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?
>
>
>
>
>
>
>
>
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