ION8650 - kWh delivery data stuck

[TJ22]

Hello there & good morning,

My name is Teja, I have an issue with the ION8650, where the kWh delivery data displayed on the RTU HMI is halt. The factual conditions in the field are as follows:

1. The kWh delivery value on the RTU HMI is not changing and is stuck at 2147483647 kWh.

2. Other parameters are operating normally.

3. The kWh delivery value on the ION8650 meter itself is normal; the data can be downloaded manually and matches the meter reading.

4. There have been no changes to the RTU configuration.

5. The ION8650 meter was checked using IEDScout to verify IEC 61850 communication from the meter to the RTU → the kWh delivery data is halt, while other parameters are normal.

I would like to ask whether you have encountered a similar case and what the recommended troubleshooting steps would be.

I have checked the ION8650 settings, and the only related parameter I found is data rollover. There is no configuration related to a data range limit that could cause the value to be held or freeze.

Thank you very much for your support.

[Mehran_Mehrnia · Accepted solution]

Hi @TJ22 

I believe this is related to IEC 61850 editions each meter's firmware and model supports.

The kWh delivery value stopped updating because the IEC 61850 configuration used Edition 1, where TotWh.actVal is defined as INT32. INT32 has a maximum limit of 2,147,483,647, and once that value was reached, the counter froze. Edition 2 supports INT64, which avoids this limitation.

The ION8650 meters with firmware v4.20 or later support Edition 2 (with the correct ICD file), so using the Edition 2 ICD or enabling rollover on the meter resolves the issue.

ION8650 sends very large Energy values over IEC 61850 Edition 2

IEC 61850 and ION technology - EN

Best Regards,

-Mehran

L3 Expert Advanced metering

[TJ22]

Hi Mehran,

Thank you for your explanation. This is very helpful information.

To enable the rollover function, can this be configured directly from the meter front panel, or does it need to be done using ION Setup software?

Best Regards,

Teja

[TJ22]

Hi @Mehran_Mehrnia 

I’ve checked that the energy rollover has been set to the maximum value from the beginning, but why did the counter freeze instead of rolling over to zero?

Best Regards,

Teja

[Mehran_Mehrnia]

Hi @TJ22 

Please note that when using rollovers above 10 million which is as default value as recommended by ION Setup, it will begin to lose significant digits especially when logging those energy readings.

If you choose to increase the rollover beyond default 10 million, the shown/recorded value will begin to lose precision somewhere above 16 million (where the register will seem to *freeze* for a period of time). Internally the meter is recording the value but what value is shown/recorded can not be properly represented since it is storing that value as a FLOAT32 which only have 7 to 8 digits of precision.

For example:

3,278,210,048(which is >>10million) might be shown accurately but the next available value that can be shown would be 3,278,210,304 so the reading will seem to *jump* at some point.

4F43 6584 in Float32 -> 3,278,210,048 in Decimal

Next Float32 is 4F43 6585 -> 3,278,210,304 in Decimal

3,278,210,304 – 3,278,210,048 = 256 kWh which means the larger the number becomes the bigger the gap.

https://www.h-schmidt.net/FloatConverter/IEEE754.html

Regarding your question, as explained previously, if the built CID file is based on Edition 1, it will be limited to INT32. Since the configured rollover value (10,000,000,000) exceeds the INT32 maximum of 4,294,967,296 (2^32), the meter continues logging large values internally, but when sending data via IEC 61850, it is constrained by the INT32 limit. As a result, the RTU stops updating because the value cannot increment beyond the maximum integer.

Best Regards,

-Mehran

L3 Expert Advanced metering

[Robert_Lee]

Your problem is your using Edition 1 of 61850 which only supports INT32 shown here highlighted in green below:

The maximum value of INT32 has a range of -2147483648 to 2147483647 while UINT32 has a range of 0 to 4294967296.

Edition 2 of 61850 support INT64 which has a much larger range which is approx +/- 9.2 quintillion.