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What options I have adjust Multiplus 2 AC charging current? Is it possible to do with MQTT or API request? I think that one option is do this programming AUX port to this use using 0-5V signal. If I use this method can I use 1kHz PWM signal or must it be pure DC?
This can be done with a hex protocol request via the VE-bus communications,
Command:
Reply:
‘S’ <Switch state> <Pot value> <Panel scale> 0x01 <Flags>
‘S’
Where the pot value changes the AC current.
Other methods may be possible.
Thank you for your answer. If I use AUX input and voltage adjustment to adjust charging current so can I use PWM signal? How much it needs current from controlling supply device?
It has a high input impedance but there is a 10 kohm pull-up resistor to +5V, see the pictures in this thread.
I checked the link. Have I understood right that Victron supply +5VDC itself and I must use potentiometer between AUX pins? I mean that I can't use external power supply and give 0-5VDC to Victron?
That will be OK.
You must ensure the external supply 0V is connected to the Aux input -ve terminal. It will see a load impedance of 10kohm, referenced to +5V so will have to sink current not source it.
As per the link there is a 1kohm resistor and a 5V1 zener diode which will protect against overvoltage. If it is a typical 400mW resistor it would accept a max overvoltage of 20V but that is an informed guess not published data.
I tried do this today but I can't do it correctly. I configured assistant to AUX port using MK3 and VEconfiguration software. Then I sent parameters to Multiplus 2 GX and everything seems to be ok. When I tried change voltage to AUX port between 0-5VDC so nothing happens. What I have done wrong? Must I activate assistant somewhere or do other jobs?
...you can do that with MQTT, easily (if you have a GX or Rpi with VenusOS running)....I am using it all the time.
The topic in question is N/<your VRM ID here>/settings/0/Settings/SystemSetup/MaxChargeCurrent
Set it to value: -1 when you want the setting to be off (current limited by the MP2 and/or BMS reported limit)...set it to value: X , where X is the max current in DC Amps to be allowed to charge with.
remember, that the topics starting wih N/... are for reading...change a value by publishing to the corresponding W/<your topic> , so in this case:
W/<your VRM ID here>/settings/0/Settings/SystemSetup/MaxChargeCurrent
see the dbus documentation for details on how to enable mqtt on the GX
