Re: Remote energy metering

[Kevin Hawkins <lists@xxxxxxxxxxxxxxxxx>]

The Netiom is indeed a sort of Ethernet version of the Viom although
it
has less smarts inbuilt for handling the I/O locally. Basically a Viom
has the abilty to setup interactions between its inputs and outputs that
are handled totally by the board (no attached PC required). It also has
some extra I/O features like pulse timers ets.   Now none of this is
important in the way you are wanting to use it as you will be pulling
the data from the board via a PC. A feature that the Viom does have
however is that the counters are 32 bits  allowing effectively very long
logging (months/years) before 'wrapping' occurs and the counter goes
back to zero.   Netioms counters are 16 bit ie possibly daily or less.
Dependent on how often you will be reading the counters from the board ,
and how frequently your pulses arrive this may be a consideration.

There are two Netiom boards, the standard version and the xAP version.
They differ in the protocol they use on Ethernet. xAP is a UDP based
protocol which broadcasts its data and the standard Netiom uses TCP in
a  point to point socket connection.  Possibly the standard version is
more suited to single point monitoring with a PC application.

There are DIN mounted  PSU's available but they tend to be wide too so
make sure you have enough space. Alternatively you could have a mains
socket mounted adjacent to the consumer unit and plug in a wall wart
type supply.  Phaedrus do not supply cases for the Netiom or Viom so you
will need to sort something here . Actually I have here a couple of
cases that were shipped with a previous 'cased' version of the Viom
should you decide to go that route.

I will mention one other possibility...    You could buy a Viom and
attach it to a Lantronix MSS100 serial/Ethernet device server which are
readily available (used)  for £40 or less.  This would network enable
the Viom and allow you to run an Ethernet cable. On the PC the Viom
would still appear as though it was directly connected to a serial port
so fairly easy programming.  The MSS100's are about the size of a packet
of cigarettes and also (come with) a 5V 'inline' power adaptor of
slightly larger size.  Again I can help you source these should you want.

http://www.lantronix.com/device-networking/external-device-servers/mss100.html

Kevin


Richard Parker wrote:
> Hi Kevin,
>
> I really appreciate your help with this. I think I will proceed with
the
> idea of the DRM100S, particularly because I only have three available
spaces
> - so that throws out the ethernet unit @ 9 Dins!
>
> I did some research into the Viom, and I see that there is an ethernet
> version available (the Netiom). Both versions (I think) require a 12V
power
> supply, and I presume picking this up from the unit is not possible
without
> some kind of a transformer (is there a DIN mounted 12V transformer
> available?!).
>
> I wondered then, if it was possible to achieve the same result using
the
> Netiom. I'd need to run approximately 23m of cable from my consumer
unit to
> my server, and I can't find a serial cable that long thats easy to
route
> since I'd need to chop the ends of the cables to pass them through
sections
> of wall etc. With CAT5 I can :)
>
> What do you think about the Netiom / DRM100S combi?
>
> Rich
>
>
>
>
> On 03/04/07, Kevin Hawkins <lists@xxxxxxx> wrote:
>
>> The Viom's have 16 inputs and you connect each output of the
DRM100's to
>> an input.  You configure the Viom to count the pulses that it sees
on
>> each input. It stores these counts internally.  It is a bit weird
how
>> you setup the Viom to do this but its all software commands issued
to it
>> over a serial port (setup by your software).    Now you can also
send
>> requests to the Viom , again via the serial port to report the
current
>> count for each of its inputs, which would correspond to the number
of
>> pulses it has received from the DRM100 ie the energy consumed.  So
you
>> effectively can read the meter this way. You can also preset or
zero the
>> counters.  The DRM100s at 1 DIN width are great - your Ethernet
unit was
>> 9 units wide.
>>
>> In your software you would just periodically read these values to
get
>> the KWHr consumed since the last reading, you may choose to reset
the
>> counters after a read.. You can do this as often as you wish -
right
>> down to a few secs apart should you wish. The only thing you must
do is
>> read counters before they overflow/roll over so that the values
are
>> valid. This is obviously dependent on the 'sensitivity' of the
meter (#
>> pulses per KWHr).  I use the most sensitive versions and I get
peak
>> pulses of over 1 per second sometimes. How large the counter
(number of
>> bits) and how often you read these can thus be calculated.
>>
>>    Kevin
>>
>>
>>
>>
>> Richard Parker wrote:
>>
>>> Hi Kevin,
>>>
>>> Like the idea of the DRM100S, and I'm all for spending
£50 on the Viom
>>>
>> vs.
>>
>>> £350~ for the ethernet device. I certainly wouldn't want
to consider
>>>
>> using
>>
>>> the ethernet device to track consumption through each MCB as
that'd get
>>> quite expensive. But the idea of using multiple DRM100S
connected to the
>>> Viom sounds perfect, especially since I could start with just
1 DRM100S
>>>
>> and
>>
>>> expand if I wanted.
>>>
>>> How can the DRM100S be connected to the Viom?
>>>
>>> Thanks
>>>
>>> Rich
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>
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