Emoncms - Feed addition and subtraction

Hi,

I have a CT on my incoming single phase power to my house. On my distribution board [because my house was 3 phase and they just modded it to make it single phase] I have a red, white and blue phase that feeds off the single incomer. 

I have cts on the blue and white phases as well. I was hoping to calculate the red phase by [red=total-blue-white]

I thought this would be straight forward in emoncms but I am struggling to get this going as I only have emoncms inputs for <total>, <blue>, and <white>. 

I dont have the conventional emontx units. I use a arduino mega with my own emontx shield. I pub the emontx data [from calcVI()] via MQTT to my MQTT broker. I then have mqttwarn [I had initially intended using the mqtt module for emoncms] subscribe to those messages and publish json to emoncms. This works well for me ito getting the data into emoncms.

Can someone please help me determine how to create a red phase feed with this calculation:[red=total-blue-white]

thanks in advance

Jason

Robert Wall's picture

Re: Emoncms - Feed addition and subtraction

How the data gets in to emoncms makes no difference. I'm guessing that your three "phases" feed different areas and you want that level of detail. You want something like:

In the Input for node "total"

log to feed (total) [to preserve the total]
-input (blue)
-input (white)
log to feed (red)  [you wanted this]

nubble's picture

Re: Emoncms - Feed addition and subtraction

Thanks Robert. This works like a charm. 

Im still a bit confused about how exactly the input processing works despite reading the docs. And in 8.3.5 on WAMP server I think there is some bug because the input process list remain empty, yet when viewing the inputs, one can see the processing associated to it.

 

 

Robert Wall's picture

Re: Emoncms - Feed addition and subtraction

I'm afraid I've given up Windows and joined the land of the Penguin, so I can't help you any more with WAMP.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.