question

The approach I took was just to control everything with the grid setpoint. A negative value is export a positive value is import. The system will try to do this but still manage everything else. For example if you set the grid setpoint to -4400 (max export for a multiplus 5000) it will try to export but if you use too much power it will just export what it can.

The modes I settled on were:

• Max export: grid setpoint at -4400
• Grid pass through: dynamically set the setpoint to the consumption value (import what is used)
• Hold battery: setpoint at solar minus consumption (i.e export excess solar rather than charge). Although as I write this it probably could be combined with the above.

I used offsets and min SOC values to put limits where appropriate. Below are some screenshots of my programming.

To help it make sense, I have an EV charger and heat pump on the AC input side, so these are calculated out so I can see them separately in the Loxone app, and the rest of the house is after the multiplus on AC1 output. AC2 output is a socket in the garage controlled by the Cerbo relay.

I hope that helps.

I made some research and now I'm able to control my system from Loxone. I have only one problem with register 2704 (Inverter power limitation). When I write some value to register when is limimiting not active, limiting became active and set to send value, but I don't know how to disable it again.

Hi, you have to write 0 to deactivate and allow full discharge power. I use in my project 2702, just 0 to disable discharge battery, or 100 to enable discharge battery.

I assumed just from reading the register, without using it. I made some testing today, behaviour of 2704 register is strange. Partialy like 0%/100%

Writing 0, Discharge is not allowed, using grid for loads only.

Writing positive value e.g. 1000, discharging allowed, but without any limit, reading register shows value 1000

Writing back 0 value discharging not alowed

Writing negative value e.g. - 11000, discharge still not allowed, reading register still 0 value

Writing negative value -35000, discharging allowed again, but reading register shows value of 30536

Strange, but I do not use this register in my project, as I mentioned I use 2702 only for 0/100%. After finishing the test I wrote value 0, discharging was not allowed, but it was not possible to switch back by using register 2702, I had to go to console, ESS seting and manually switch of "Limit inverter power". After this my project is working again with 2702.

My DVCC is Forced ON, 2702 is working well. What wersion of TCP register list do you have? I work with 3.10 verision right now, nothing written there about this limitation. I just checked document version sheet of my register list and found interresting comment related to 2704 - "Make ESS max discharge current (2704) int16 so it can take -1 (disabled) as value" .... this is different information to what is written as description of 2704 in register list.

I made some more tests and I have found, that writing to register 2702 is working even DVCC is enabled, but not displayed in VenuxGX menu. I use VenusGX with VenusOS 3.13. With register 2704 I can write maximum discharge current, limitiation is active but not seen in menu to until buton Limit inverter button is set to on.

I have one more problem. I'd like to disable battery charging from solar charge controller when is energy sell profitable, but I don't know how to do it. Register 2701 is not working with DVCC enabled and register 2705 is not working when Feed in is enabled. Is it way how to get this working?