Re: Simat 1 wire Hubs

["Frank Mc Alinden" <frankmc@xxxxxxxxxxxxxxxx>]

Hi Jon

> Whereas I could do:
> 1. for all temperature sensors
>      1.1 lock 1-wire bus
>      1.2 select next temperature sensor
>      1.3 start temp conversion going
>      1.4 release 1-wire bus

I atke it you mean here rotate thru and start conversion on each sensor

> 2. delay for 750ms (although this could be optimised somewhat)
> 3. for all temperature sensors
>      3.1 lock 1-wire bus
>      3.2 select next temperature sensor
>      3.3 read temperature
>      3.4 release 1-wire bus

Likewise rotate thru and read the conversion values ???........Does sound a
much quicker way to do it.......
> And then if other sensors need polling I should really optimise it
> according to their location on >the bus so the same path isn't
opened
> multiple times when it doesn't need to be.

That makes sense.........

I notice on my two hubs that the branches are polled approx every 3 to 4
seconds but i currently only have a  single temp sensor connected to
each...Im not sure how the polling is done on the OPN-NODE....im hoping its
done similiar to what your suggesting .....will find out soon how
responsive
the network will be once my moisture sensors arrive......

Did you relocate your lcds and iBUTTONS onto the main trunk ???

Frank


----- Original Message -----
From: "Jon Payne" <jgpayne@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Tuesday, May 22, 2007 6:14 PM
Subject: Re: [ukha_d] Simat 1 wire Hubs


> Yes, 750ms at 9-bit resolution, and on my TINI it takes almost 1.5
seconds
> because there are other threads running (although I need to re-measure
> because I've just changed to timer based rather than thread based so
it
> should speed up a bit).
>
> Another issue I have with the default 1-wire library implementation is
> that it is just implemented as a delay, so to poll all temperature
sensors
> I do this at the moment:
> 1. lock 1-wire bus
> 2. select next temperature sensor
> 3. set temp conversion going
> 4. delay for 750ms
> 5. read temperature
> 6. deselect temperature sensor (close the path to the device)
> 7. release 1-wire bus (to let other's use the bus)
> 8. goto 1
>
> So for n sensors it takes n * ( time to open path +750ms + time to
close
> path) at best.
>
> Whereas I could do:
> 1. for all temperature sensors
>      1.1 lock 1-wire bus
>      1.2 select next temperature sensor
>      1.3 start temp conversion going
>      1.4 release 1-wire bus
> 2. delay for 750ms (although this could be optimised somewhat)
> 3. for all temperature sensors
>      3.1 lock 1-wire bus
>      3.2 select next temperature sensor
>      3.3 read temperature
>      3.4 release 1-wire bus
>
> Which would be faster. And then if other sensors need polling I should
> really optimise it according to their location on the bus so the same
path
> isn't opened multiple times when it doesn't need to be.
>
> Hmmm... all a bit more complicated than I wanted...
>
> ----- Original Message ----
> From: Frank Mc Alinden <frankmc@xxxxxxx>
> To: ukha_d@xxxxxxx
> Sent: Tuesday, 22 May, 2007 7:33:40 AM
> Subject: Re: [ukha_d] Simat 1 wire Hubs
>
>
> Hi Jon
>
>>now I'm thinking that it slows down the 1-wire network too much for
my
>>purposes.
>
> Yeah i noticed that the branches get polled.....Im going to put
moisture
> sensors and any outdoor temp sensors on the Hub  and my Ibuttons on
the
> main
> trunk along with the lcd that i have just ordered.. Dont for get
though
> Jon
> it take approx 700mSEC to read a dallas temp sensor this delay is not
due
> to
> the HUB.....Luckily my room temp sensors connect to my Probe system so
> that
> will reduce the scan time a bit.....I,ll have  a play with the lcd
> connected
> to the HUB to see what sort of delays i get.......
>
> Frank
>
>
> ----- Original Message -----
> From: "Jon Payne" <jgpayne@xxxxxxx>
> To: <ukha_d@xxxxxxx>
> Sent: Monday, May 21, 2007 10:08 PM
> Subject: Re: [ukha_d] Simat 1 wire Hubs
>
>
>> Yep, same as you really I dusted it off about 1 year ago... now
I'm
>> thinking that it slows down the 1-wire network too much for my
purposes.
>> With a couple of LCDs, a few ibutons, DS2406's, and about 8
temperature
>> sensors it takes 10 seconds to scan for the presence of devices on
the
>> network, during which the network is locked out, before I've even
polled
>> existing devices: about 20 seconds for temperature sensors (with
most on
>> the same branch). This means for example a message needing to be
>> displayed
>> on an LCD is delayed for too long.
>>
>> ----- Original Message ----
>> From: Frank Mc Alinden <frankmc@xxxxxxx>
>> To: ukha_d@xxxxxxx
>> Sent: Monday, 21 May, 2007 12:30:04 PM
>> Subject: [ukha_d] Simat 1 wire Hubs
>>
>>
>> Hi Guys
>>
>> Just got round to trying out my  Simat 1 wire hubs...Cant believe
they
>> have
>> been gathering dust that long  i think  that  we  had a bulk buy
back
>> around
>> July/sept  2002 ;-)...
>> Anyone on the list who got one using theirs ;-)
>>
>> Frank
>> www.armaghelectrical.com.au
>>
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