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Re: Re: Serial protocol questions
Here is what I was thinking. Give me your thoughts. This does not address
the Master-->XPL conversion.
System Layout:
RS232āDedicated MasterāRS485āSlave
Protocol RS232āMaster:
<Slave Addr><Length><Command><Data.><Chk Sum>
Slave Addr = Slave Address 1-255 (0 = All devices)
Length = Message Length including from Slave Addr to Check Sum (4-255
bytes)
Command = Single byte control messages (1 byte)
Data = The actual Data to be processed by Slave (Variable Length)
Chk Sum = Check sum this is a byte add of string (1 byte)
Master RS485āSlaves
<STX><Slave
Addr><Length><Command><Data.><Chk
Sum><ETX>
STX = Start byte (02)
Slave Addr = Slave Address 1-255 (0 = All devices)
Length = Message Length including from Slave Addr to Check Sum (4-255
bytes)
Command = Single byte control messages (1 byte)
Data = The actual Data to be processed by Slave (Variable Length)
Chk Sum = Check sum this is a byte add of string (1 byte)
ETX = End or Terminator Byte (03)
----- Original Message -----
From: "DynamoBen" <ben@xxxxxxx>
To: <ukha_xpl@xxxxxxx>
Sent: Monday, January 24, 2005 2:56 PM
Subject: Re: [ukha_xpl] Re: Serial protocol questions
>
> 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
>>>> <http://www.xpl.myby.co.uk>
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>>>>
>>>>
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>>>>
>>>>
>>>>
>>>>
>>>> [Non-text portions of this message have been removed]
>>>>
>>>>
>>>>
>>>> xPL Links: http://www.xplproject.org.uk http://www.xplhal.com
>>> http://www.xpl.myby.co.uk
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>>>
>>>
>>>
>>> xPL Links: http://www.xplproject.org.uk 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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>
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