question

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zeron asked

Node Red : update frequency on Victron nodes

I have a Multiplus-II 5000, Cerbo GX and "tore" meter connected to the Multiplus' 3.5mm jack input.

I'm trying to use node red to turn on/off various appliances (EV charger, water heater, ...) to manage spare solar power but there is one major hiccup : measuring AC output through Victron nodes only gives me a value every 5 seconds, which is way too slow and the EV charger keeps turning itself off because it expects much faster udpates to both stay on solar charging or not trip the main breaker.

Is there any way to get a faster refresh rates on Node Red?

Would I get a much better update speed using Modbus TCP? (I'm trying to figure that one out also, but even with a Modpus polling client and the Victron excel sheet I can't seem to find where the values I want are)

Will I not get fast enough updates from the Multiplus and should I get an external energy meter?

Energy MeterNode-RED
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Dirk-Jan Faber (Victron Energy) avatar image Dirk-Jan Faber (Victron Energy) ♦ commented ·

Alternative you can also install https://flows.nodered.org/node/node-red-contrib-victron-modbus and use that for polling more frequently.

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zeron answered ·

I looked the node-red-contrib-victron source code and found this :

class VictronDbusListener {
  constructor (address, callbacks) {
    this.address = address
    this.pollInterval = 5

It looks like it's hardcoded to poll at a 5s interval without it being specifically a node red limitation so I can give it a try by modifying it myself. Or is there any reason to not poll modbus too frequently ?

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Dirk-Jan Faber (Victron Energy) avatar image Dirk-Jan Faber (Victron Energy) ♦ commented ·

You can try to increase the frequency, but I doubt it will help you much. You are right that, default, it polls for the value once every 5 seconds. But besides that it will also output on each "ItemsChanges" and "PropertiesChanged" on the dbus. So in practice it will already give more frequent output.

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zeron avatar image zeron Dirk-Jan Faber (Victron Energy) ♦ commented ·
Thanks this made me realized something was wrong since I was only getting an update every 5s no matter what : turns out a some bad file on the Cerbo was preventing the updates on victron's node and I was stuck 7 versions behind.


Before doing this I had changed pollInterval to 1s and would get an update (with a new value by having a filter node) every 3-4s on average.

After doing the update to latest version and reverting pollInterval to 5s I still get as regular updates as fast polling so the "changed" triggers seem to now working as intended.

I'll check again soon if that's fast enough for the EV charger to regulate itself.


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