question

svalvasori avatar image
svalvasori asked

Cerbo GX Digital Input / Active Role

I'm looking for confirmation that the digital inputs on Cerbo GX are 5VDC (as in will not support 12-15VDC). I saw this in one image but have not found further confirmation. If that is the case I would need to drive the inputs with relays that are triggered by the 12V action I wish to monitor.


2nd Question - With a Multiplus charger/inverter, smartshunt, MPPT, and lead acid batteries - exactly what active role does the Cerbo GX take? It looks like active roles are generator start (I'm not interested in this) and DVCC. DVCC with no ESS and lead acid, from the chart in the manual - continue to use internal charge algorithms. Unless I misunderstand what ESS is, but this installation is on a boat - nothing is going back into the grid. I see it can share voltage, current and temperature (perhaps someone can explain why this is critical or valuable vs using each devices own values).

I'm struggling to understand what the Cerbo GX will do for my setup. I'm already a SignalK user, so while the reporting and VRM is awesome, I already have that functionality. The hardware is nice, I can see value in the ease of installation, with the VE.direct ports and VE.can. Also the temperature and digital IO could be useful. So, I'm likely to purchase the Cerbo GX (without monitor), use it as a connectivity hub and pull the data into SignalK for display and graphing. I love the open source flexibility of Victron gear, and as such may opt to install SignalK and NodeRed on the Cerbo GX to run a small display in the salon, so I can report on both legs of my AC input.

I can justify Cerbo GX just for the hardware connectivity and extra inputs alone, but I would really like to understand how or if it will actually co-ordinate the MPPT and Multiplus to do a better job of keeping my batteries charged.

Please don't see this as argumentative, I'm simply trying to understand.

cerbo gx
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2 Answers
Mark avatar image
Mark answered ·

I’ve used a 4 channel opto-isolator,to convert my 12v outputs to 3.3v for input to the Cerbo........

works flawlessly

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tslewis99 avatar image tslewis99 commented ·

can you provide a link to the opto-isolator that you use?


Thx



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pwfarnell avatar image pwfarnell tslewis99 commented ·

Have a look at this thread, there is a link in one of the answers to a suitable device.

https://community.victronenergy.com/questions/113996/how-do-i-use-the-digital-inputs-in-cerbo-gx.html

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mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi, its indeed 5v maximum. And I see its missing in the manual as well as the spec sheet.


I’ll get that included; thank you!

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rlynch03 avatar image rlynch03 commented ·

Thanks for confirming the voltage but I do not think that info has made it into the manuals yet.

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mvader (Victron Energy) avatar image mvader (Victron Energy) ♦♦ rlynch03 commented ·

Hi thanks, I see what you mean. I've asked for the info, copied below, to be added to the chapter.


The inputs are non-isolated. They operate at 3V3 levels, and can withstand up to 5V input. Each input has an internal 10k pull-up resistor to 3V3. We recommend wiring it to a potential free relay or otherwise open collector/optocoupler output.

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