making use of programmable relays in ESS

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petajoule asked Nov 19, '19

making use of programmable relays in ESS

Given medium size(?) installation:

3 x Quattro 5kVA in 3-phase configuration

2 x MPPT 250/85 - evidently DC coupled

1 x Fronius Symo - AC coupled

1 x Venus GX

on last count, the docs mention a total of 13 (2 x 1 of the MPPTs, 2 in the Venus GX and 9 in the Quattros) programmable relays, where the 9 (3 x 3) of the Quattros probably behave like just 3 (yes?) in sync.

I'm missing the relay functions in Venus and Quattros under ESS operation. There is docs for the MPPT relay functionality.

Ideally, I would like the Venus GX relays to indicate various "excess energy" states. I can get a "battery full", but on top of that I would need

* "MPPTs are (about to) being throttled"

* "Fronius is (about to) being throttled"

So this could trigger some consumers to shave off some of the excess energy. HowTo?

ESS Relay

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usernamepasswordbs commented · May 02, 2023 at 06:46 AM

#Petajoule Did you get anywhere with "MPPTs are (about to) being throttled"?

Is it in the code somewhere?

Much appreciated if you can tell me.

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Modifications Space

Node Red Space

Answer 1 · 2019-11-19T09:23:56Z

mihair answered · Nov 19, 2019 at 09:23 AM

As far as I know, you can use either dbus or node-red

Personally I prefer to define a script using dbus and then to run it with crontab.

As an example of controlling relays:

#dbus -y com.victronenergy.system /Relay/1/State SetValue 1

Above command will set Relay1 ON (close contacts)

you can check if it is closed or not by issuing :

#dbus -y com.victronenergy.system /Relay/1/State GetValue

Please use dbus-spy to get all the paths for you script

As another example, here is a small script which I use to interrogate EM111 grid meter for TotalEnergy, L1 AC voltage and current:

#!/bin/bash

RE=`dbus -y com.victronenergy.grid.cgwacs_ttyUSB2_di32_mb1 /Ac/Energy/Reverse GetValue | awk '{printf("%d\n",$3 + 0.5);}'`

FE=`dbus -y com.victronenergy.grid.cgwacs_ttyUSB2_di32_mb1 /Ac/Energy/Forward GetValue | awk '{printf("%d\n",$3 + 0.5);}'`

TE=$(($FE+$RE))

echo Total Energy $TE kWh

ACC=`dbus -y com.victronenergy.grid.cgwacs_ttyUSB2_di32_mb1 /Ac/L1/Current GetValue | awk '{printf("%d\n",$3 + 0.5);}'`

echo Current $ACC A

VCC=`dbus -y com.victronenergy.grid.cgwacs_ttyUSB2_di32_mb1 /Ac/L1/Voltage GetValue | awk '{printf("%d\n",$3 + 0.5);}'`

echo Voltage $VCC V

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petajoule commented · Nov 19, 2019 at 11:16 AM

Thx. It looks dbus is offering all the data necessary.

Unfortunately I seem to have trouble reading out any values:

root@ccgx:~# dbus -y com.victronenergy.system/Ac/ConsumptionOnOutput/L1/Power GetValue
root@ccgx:~# dbus -y com.victronenergy.system/Ac/ConsumptionOnOutput/L1/Power         
/
root@ccgx:~#

And omitting -y is even more adventurous.

root@ccgx:~# dbus com.victronenergy.system/Ac/ConsumptionOnOutput/L1/Power GetValue
Traceback (most recent call last):
  File "/usr/bin/dbus", line 302, in <module>
    bus = dbus.SessionBus()
  File "/usr/lib/python2.7/site-packages/dbus/_dbus.py", line 211, in __new__
    mainloop=mainloop)
  File "/usr/lib/python2.7/site-packages/dbus/_dbus.py", line 100, in __new__
    bus = BusConnection.__new__(subclass, bus_type, mainloop=mainloop)
  File "/usr/lib/python2.7/site-packages/dbus/bus.py", line 122, in __new__
    bus = cls._new_for_bus(address_or_type, mainloop=mainloop)
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NotSupported: Using X11 for dbus-daemon autolaunch was disabled at compile time, set your DBUS_SESSION_BUS_ADDRESS instead

Still sitting here on 2.33, but that shouldn't be the problem - should it?

I should mention that dbus-spy seems to work well, so it doesn't look like the system would be broken or something. Just the method getting info via shell doesn't work for me.

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Answer 2 · 2019-11-19T11:20:18Z

petajoule answered · Nov 19, 2019 at 11:20 AM

root@ccgx:~# dbus -y com.victronenergy.system /Ac/ConsumptionOnOutput/L1/Power GetValue
443

A space a day, keeps dbus at bay.

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mihair commented · Nov 19, 2019 at 12:36 PM

If you wanna get something like 433 W, then use GetText instead of GetValue

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petajoule mihair commented · Nov 20, 2019 at 08:39 AM

GetValue is fine, as we need to make comparisons of the value (arg1 -ge arg2) etc.

Still fighting here to use dbus-send directly instead of dbus -y, as the latter is slow as ... metabolism result.

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Answer 3 · 2019-11-20T09:00:20Z

petajoule answered · Nov 20, 2019 at 09:00 AM

A few more questions remain:

How's the return value after a SetValue to be interpreted?

root@ccgx:~# dbus -y com.victronenergy.system /Relay/0/State SetValue 1
0

Or here:

root@ccgx:~# dbus -y com.victronenergy.system /Buzzer/State SetValue 1
2

And how can one make sure the value set also remains set?

e.g. setting that buzzer, it blips shortly and is then off again. Haven't checked the relay, but I assume that wil lbehave the same?

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