Solved Energy Meter kwh Reset

[MikeyH]

Hi All,

I have an energy meter I am using, connected via Modbus. The issue I have is the kwh figure in the meter can not be reset to zero, currently it is up to 9124.0 kwh. When I start a new test I'd like to reset the logged kwh figure.

What is the best way of doing this via the REX program? I wondered about saving the last know value from the Modbus register and then subtracting that to give me a virtual reset and start from zero again.

Thoughts?

Cheers

Mike

[reitinge]

@mikeyh Hi Mike,
one possibility is to use a SHLD block with Triggered sampling mode (documentation here). When you send a pulse to the block input SETH, the current value of input u is stored at output y. The overall connection can then look something like this:

Cheers,
Jan

[MikeyH]

@reitinge Hi Jan,

That works extremely well, even better once made into a small subsystem! Thank you for your help as always.

Cheers

Mike

[Apollo]

@mikeyh

Maybe you can also make the parameters of function block SHLD non-volatile (Persistent parameters).

If you restart your computer and/or download new program then it will not lose the previous stored value.

And storing the value every midnight in a database and then trigger the SETH input would give you a nice overview of the daily consumption.

[reitinge]

Hi guys,
@mikeyh you're welcome. @apollo is right with persistent parameters. If you don't just do short-term tests, don't forget to turn persistent parameters on.

[MikeyH]

This post is deleted!

[MikeyH]

Hi Both,

Thank you. @Apollo, great tip. That will save me loosing data.

Cheers

Mike