Very odd readings

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aquarat
Posts: 7
Joined: Mon Sep 24, 2012 5:40 am

Very odd readings

Post by aquarat » Tue Jan 08, 2013 11:35 am

Hi

One of my EKM Omnimeters (V3) is behaving very strangely. It sits in a box at a client's premises. My application reads values from it at intervals of 2 minutes.

On the 5th of January the network connection went down and it didn't come back up until today, the 8th when I logged into the router locally and rebooted it. When network connectivity was restored, my application automatically continued querying the meter for the latest data.

The meter's total kwh reading jumps from 2913.3 (2013-01-05 15:59:39 GMT+2) to 281.4 (2013-01-08 13:06:03 GMT+2)... which shouldn't be possible ? I haven't seen this happen so far. Is this value reset if there's a power failure ?

Contact with the meter was lost for approximately 3 days, the reading after exactly 3 days of lost contact was 314.4 kwh, which is an average of 104.8 kwh per day. The average daily meter readings so far have been 101.2 kwh... so it's like something happened which caused the total kwh reading to be reset to zero.

Anybody have any idea why this happened ? I was under the impression that the total kwh reading could not be reset ?

Help :(

ianf
Posts: 7
Joined: Fri Jul 06, 2012 12:01 am

Re: Very odd readings

Post by ianf » Tue Jan 08, 2013 11:54 am

I had something similar happen to one of my meters where some of the internal settings were corrupted by a slew of power failures and brown-outs. If your kWh counter now runs at a different rate you have the same issue I had (mine ran at 1 tenth pace). Setting the CT ratio back to the original value (200) should fix the measurement, but the kWh counter continue from its current value sadly. Incidentally, what is the firmware version on your meter?

aquarat
Posts: 7
Joined: Mon Sep 24, 2012 5:40 am

Re: Very odd readings

Post by aquarat » Tue Jan 08, 2013 2:34 pm

I've just tried reading meter data using EKM Dash and it's refusing to read anything other than the "General" and "Advanced" tabs (it complains when I click on rates and Data).

The brown-out scenario makes sense; a complete power cut would have caused the 3G router to have rebooted... but a low voltage outage would have caused the voltage on the DC output from the transformer on the router to have dropped, perhaps to a point where low-power components like the RAM and CPU would have continued to function, but high-power components like the USB 3G dongle would have reset. This makes even more sense when it appears the router's 3G modem and the EKM Meter both reset at what appears to be the same time.

I will have to amend my application's code so that it can accurately report on meters that produce this kind of issue (by storing a base value for each meter in the configuration).

Thanks for the hint Ianf.

ianf
Posts: 7
Joined: Fri Jul 06, 2012 12:01 am

Re: Very odd readings

Post by ianf » Tue Jan 08, 2013 11:59 pm

aquarat wrote:I've just tried reading meter data using EKM Dash and it's refusing to read anything other than the "General" and "Advanced" tabs (it complains when I click on rates and Data).
Yes, that will most likely be the iSerial TCP retransmit bug I mentioned in another thread. You're possibly getting a large number of CRC errors at the moment. Contact me in a PM with your email address and I'll give you the firmware image with the fix. I don't want to post it here because I'm not sure what EKM's stance is on giving it to the masses.

Ian

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