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Pylontech US3000C and RCT Axpert 5KVA VMIII - comms issue

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Hi.

 

I've been running 3x US3000 with an RCT Axpert 5KVA VMIII for a while now.  I decided to add an extra battery and received the US3000C.  I've made the US3000C the master (I was told that I have to) then set dip switch 1 to on on the master and all other dip switches on the slaves to 0.

 

When plugging in the original comms cable I started getting the error 61 (no comms) error on the inverter.  After some digging here I found that the cable pinouts have been changed.  Using the pinouts found in a doc on another thread (pin7 -> pin5) and (pin 8 -> pin3) the error 61 stopped, but now i getting error 04 (low battery).  Seems like the inverter connects to the battery but cannot read the correct battery capacity.

 

Not sure if I have to upgrade firmware maybe, or I need a different cable?  Can anybody help?

My current firmware versions are:

U1 -> 41.03

U2 -> 02.00

U3 -> 00.21

 

Pin outs:

image.png.b3709c54d39596cf2159f11c9937ed20.png

39 minutes ago, chmmmr said:

Not sure if I have to upgrade firmware maybe, or I need a different cable?  Can anybody help?

My current firmware versions are:

U1 -> 41.03

U2 -> 02.00

02.00 is very early removable display firmware. That's where all the Pylontech protocol code resides. You could update to 02.66, available from this forum's file section. It's the same firmware as for Axpert King removable displays.

  • Author

Thanks @Coulomb.  I found version 02.66 removable display unit in the downloads section.  I will try flash it as soon as I can get a USB to COM port adapter.

I assume my main firmware is also old then, but I can't seem to find the latest VMIII firmware in the downloads section.  Could you help me find it.

 

Also, what is the chance of bricking the unit from flashing it with an incompatible version or something?  Will all VMIII firmware files work with my RCT Axpert VMIII?

5 hours ago, chmmmr said:

I can't seem to find the latest VMIII firmware in the downloads section.  Could you help me find it.

The latest DSP files for VM IIIs are on the Czech site. The dates for the VM3.hex files are:

41.08: 2020-01-10

91.20: 2020-08-28

41.16: 2020-09-03

41.17: 2020-12-25 (Christmas day! Possibly an ordinary work day in China and Taiwan.)

The availability of firmware update files varies tremendously. It looks like the 41.xx files have larger numbers for later firmwares, as you'd expect, but the 90.xx files are all over the place, and some are for Axpert MAXs! So 41.17 should be a reasonable update from 41.03.

5 hours ago, chmmmr said:

what is the chance of bricking the unit from flashing it with an incompatible version or something?

Low but unfortunately not zero. I have a post for if you think your inverter is bricked (not specifically for VM IIIs).

5 hours ago, chmmmr said:

Will all VMIII firmware files work with my RCT Axpert VMIII?

Yes.

Hi there.
I’m talking under correction.

The manual shows ADD switches ,Dont think you have to select any of them for the master or slave in the us3000c .

Page 6.
ADD Switch
Dip1: RS485 baud rate 1: 9600; 0: 115200
Dip2~4, reversed.

Edited by Piper

  • Author

@Coulomb I think may have messed something up.  I tried to flash the removable display unit, I downloaded the 2.66 rar file, ran the Remote Panel_ReflashTool.exe app, clicked on flash dsp.  The screen is now blank and the error in the console window says cannot find `dsp.hex`.  I now see there is only a mcu.hex file in that folder.  Not sure if i've bricked it, but where can I find a dsp.hex file to try recovery from?

  • Author
1 hour ago, chmmmr said:

@Coulomb I think may have messed something up.  I tried to flash the removable display unit, I downloaded the 2.66 rar file, ran the Remote Panel_ReflashTool.exe app, clicked on flash dsp.  The screen is now blank and the error in the console window says cannot find `dsp.hex`.  I now see there is only a mcu.hex file in that folder.  Not sure if i've bricked it, but where can I find a dsp.hex file to try recovery from?


ok that was a bit of a panic post :)  I click flash mcu and after the flash the screen came back to life.  Pylontech setting now connects and doesn’t complain about low battery. 
 

Also did the main firmware update and everything looks ok so far. 

On the inverter now when I press up the U3 says 88.88  I guess that is the dsp?  Is that a problem?

Thanks for your help. 

Edited by chmmmr

3 hours ago, chmmmr said:

ok that was a bit of a panic post :)  I click flash mcu and ...

Yes, the "flash DSP" button or whatever it's called is a trap 🪤. Nothing good comes of clicking it, as far as I can tell. I certainly would not let it near a dsp.hex file.

3 hours ago, chmmmr said:

On the inverter now when I press up the U3 says 88.88  I guess that is the dsp?  Is that a problem?

No, U3 is something else, I think the Bluetooth or Wifi firmware. 88.88 seems to mean "I don't know" or "not present". The DSP firmware is U1.

Edited by Coulomb

  • Author

Looks like everything is still working, bluetooth etc.  Hopefully going from having a version on U3 to no version is ok.

 

Thanks for all your help.

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