Hi All 

So I am upgrading from Lead Acid to Li-ion and thought I might as well also do the firmware. 

I have an RCT Axpert 5KVA VM3  inverter

I never received the illusive communication cable in the box and at the time did not really think to much about it. It was an insurance replacement. TLDR; this cable is what I need

Following the various forums here and reading quite a bit, I saw that I can update the firmware via the downloaded firmware I got from Coulomb's link. Everything connected fine and seemed okay via USB and then it errored out and I got error message 32 which is a communication error between display and inverter and to rectify this you need to load the MCU firmware update. 

Here is the issue, I need the Network cable to serial and then serial to usb or I am assuming network to USB cable and I doubt the male to female plug does anything to the connection. 

And that is like trying to find hen's teeth. I have spoke to a couple of local installers who do Axpert and it seems that there are only a select few who do the firmware upgrades and when I contacted them I got blown off because I did not buy the inverter from them and should try the people I bought it from. 

I am based in Pretoria so any help would be appreciate as to how I can get this done. I can also crimp my own cable if needed and get a network to USB converter I am sure but am also struggling to find that info. Lots of info on the Network to BMS for pylon tech but very little on Inverter to serial and where to get the needed cable. 

Thanks

Hi All

Just an update. 

I was showing the installer for the battery what I did and how the inverter was still seeing the install command etc. 

Then did the classic... and when I run it, it fails, like so.... and it ran and update the firmware. 

I still get an error 32 when the inverter is off, but, everything else is working as it should. 

Still a concern that you cannot get the cable  after market but for now I will not sit in the dark

2 hours ago, javadog said:

Still a concern that you cannot get the cable  after market but for now I will not sit in the dark

Good to see that you appear to be sorted for now.

The USB to RS-232 adapters are widely available; it's just that some work better with Axperts than others.

The RS-232 to RJ-45 cable (it's not networking cable, it just uses the same connector at one end) you can make yourself. You can cut a networking cable in half or crimp your own cable to an RJ-45 plug, and solder wires to a female D9 connector. The required pinout is here.

Edit: There is a brief discussion of USB to RS-232 adapters in the firmware upload instructions. The first post of that thread is an index, and has links to places in South Africa where you can buy known-good adapters.

Edited April 14, 20231 yr by Coulomb

As always thanks Coulomb!