IHD data and smart meter data correspondence

Reed_Richards

I have just found that I cannot download any half hourly smart meter readings beyond 8 am on 20th July. I had a similar problem for 11 days in March 2024 and that missing data was never recovered.  As before, the WAN and HAN lights flash every 5 seconds so there is no indication of a communication problem  

This time I switched on my IHD, which had been off for several months, to see what it knew.  It can tell me my hourly electricity consumption for today, my daily consumption since Thursday 21st July, weekly for up to 5 weeks ago and monthly for every month back to July 2024.

My question is whether my IHD derives this information from "doing sums" on the stored half-hourly data or whether the data it needs to report to the IHD is stored separately.  If it is the former that means that the half hourly data is being "remembered" even though it hasn't been downloaded to the DCC for some reason.            

Scot_39

I've always assumed thats just read from the meter itself and its requirement to store historical totals

Say for electric, from

https://assets.publishing.service.gov.uk/media/5a796c9e40f0b642860d7fa9/smart_meters_equipment_technical_spec_version_2.pdf

5.6.4.11 Cumulative and Historical Value Store

A store capable of holding the following values:

i. nine Days of Consumption comprising the current Day and the prior eight 

Days, in kWh and Currency Units;

ii. six Weeks of Consumption comprising the current Week and the prior five 

Weeks, in kWh and Currency Units; and

iii. fourteen months of Consumption comprising the current month and the prior 

thirteen months, in kWh and Currency Units.


But could ve completely wrong.

My ihd actually goes wrong between midnight and 1 am dst on the appropriate times on my ihd, so daily looks a day out etc until just after 1am.


As meters iirc always store and timestamp using utc gmt afaik

Not sure if thats the meter or tge ihd misinterpreting it though.

Scot_39

Was  the old historic data from Mar ever retreivable on one of the apps or by supllier ?

Do they only pull thd 48 hrs data, or do they do the master registers tables as well  ?

I am sure people have persuaded their suppliers to re-request missing data, or done so themselves.

The meter is clearly not completely bricked as it were if the historic looks real and changing e.g. nightly.

Reed_Richards

My IHD will happily give me an hour-by-hour account of the power consumed this day as well as everything else mandated in 5.6.4.11 Cumulative and Historical Value Store.  But for whatever reason, the meter has stopped passing on the half-hourly data to the DCC, despite the fact that the WAN light flashes green every 5 seconds..  When this happened in March 2024 the missing data was never recovered.

Do smart meters have a reset facility?  I would be tempted to try that if it doesn't erase the memory (and the memory must be non-volatile to cope with power cuts).    

Reed_Richards

I was once on the phone to my supplier and, IFRC, they made a meter reading there and then.  If that's right and they can get an immediate meter reading on command, perhaps I should ask for one to see if that channel of communication is open?  

Ildhund

Reed_Richards said:

... they made a meter reading there and then.  If that's right and they can get an immediate meter reading on command,

There's all sorts of stuff that can be done remotely: SEC Appendix E - DCC User Interface Services Schedule. Whether one of those requests represents the 'reset' function you were looking for I couldn't say. 

As regards the volatile memory, I think the on-board Li battery is supposed to keep it alive for some hours as well as keeping the clock ticking over during a power outage. 

Swipe

Scot_39 said:

My ihd actually goes wrong between midnight and 1 am dst on the appropriate times on my ihd, so daily looks a day out etc until just after 1am.

Mine does exactly the same