PM8240 meter modbus register 30108 Issues after firmware update

[JarrydWebber]

Good day all

We have recently performed some updates on our PM8240 meters, updating the firmware, from V2.1 and V3 up to the latest V4.0.0
We have noted that the performance of the values reported on modbus register 30108 have changed.
Register 30108 is mapped to "Apparent Power Total Last Demand".

In the below screen capture of a log of this register, the behavior changed on the 30th June.

Before the update the log was reporting consistently high values (~1200 kVA) while after the update it reports ~10kVA and occasionally jumps to the previous high values.

The setup of the meter is exactly the same as it was, and we have compared it against meters that we have not updated yet, and the ion settings are the same.

Does anyone have any indication as to what might be happening here?

[Charles_Murison · Accepted solution]

Hello @JarrydWebber ,

Hard to say what is happening from a picture alone. How often are you polling the modbus address? Would suggest tracing the information back through the meter's framework. Mapping from Modbus register to ION register is done through a number of mapping modules. For Modbus address 30108, this is Data mapping demand module. The ION register, "kVA sd del+rec" comes from a sliding window demand module. Would need to look at the output of this module to understand what is happening. It could be that this module update rate changed from end of interval to every second, it could be this module is linked to a reset. Hard to say for sure.

Can use ION Setup to investigate. Connect to the meter and change to advanced view. (Hold ctrl + click on meter in left panel. Setup Assistant needs to be closed.) Navigate to SWinDemand Modules -> kVA sd del+rec. Hold down shift and click on the tab Output registers, you should see the real time values each time you click. Right click on output registers and change the update rate, I would suggest 5 or every second. Watch the value of kVA sd del+rec and compare behavior between meters.

Regards,

Charles 

[JarrydWebber]

Hi Charles

Thank you so much for the advice.
It seems as though the firmware update changed the SD3 Update Rate to Each Second, while it was set to "End of Sub-Interval" previously.

It seems like this has resolved the issue. Thank you