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janosch avatar image
janosch asked

problems monitoring / controlling Hoymiles micro inverter via DTU & SunSpec (with Easysolar II GX device )

Hi,


I am trying if the Hoysmiles inverter (via their DTU) could be monitored / controlled by a Victron Multiplus II GX / Easysolar II GX via the SunSpec protocol.


Reading the Victron GX source code and Hoysmiles Modbus implementation it should work flawlessly.


--> https://github.com/victronenergy/dbus-fronius/blob/master/software/src/sunspec_detector.cpp

--> https://www.shinetech-power.de/wp-content/uploads/2021/07/Technical-Note-Modbus-implementation-using-3Gen-DTU-Pro-V1.2.pdf


Unfortunately I do not get it to work.


The Hoysmiles inverter / DTU is not being recognized on the "Modbus Device Scan" via Victron GX,

Also I cannot add it manually as a Modbus device


But worse:

After several minutes the Hoysmiles HM-1500 micro inverter is stopping to generate electricity. I haven’t found out why. (my suggestion is that the GX ModbusIP "Auto device Discovery" is crashing the Homilies DTU Pro or the micro inverter).

The inverter could only be make working again by either

- resetting the micro-inverter (in my case HM-1500) on the S-Miles cloud via "reset device") or

- disconnecting the HM-1500 from the grid


Some observations:


The communication to the HM-1500 via the DTU-PRO via ModbusIP is working not stable.

(While pinging to the DTU is working flawlessly )


Most of the times I don´t get a result from the DTU / Microinverter via ModbusIp


But Sometimes the communication via modbusIP works:

I am using the following script (with deactivated influx DB part)

https://github.com/sneerix/hm-dtu-pro-modbus-python



% /usr/bin/python3 /Users/xx/Downloads/hm-dtu-pro-modbus-python-main/hm-dtu-pro-modbus.py

2022-08-09 13:41:52

inverter number: 0

PVVoltage: 31.4 V

PVCurrent: 6.63 A

PVPower: 208.2 W

PVTodayProd: 13 Wh

PVTotalProd: 36427 Wh

GridVoltage: 242.3 V

GridFreq: 50.02 Hz

Temp: 41.3 oC

OperatingStatus: 3

AlarmCode: 9

AlarmCount: 0

LinkStatus: 263


inverter number: 1

problem reading registers


I am using the grid profile is "2.0.0 (DE_VDE4105_2 …)“

The RS485 address setting in Hoymilies S-Miles Cloud needs to be set to 0.

(but still the communication to the Hoysmiles inverters via ModbusIP is not reliable - seems to be a firmware problem of their DTU / micro inverter)

Any suggestions, how to debug it further?

Anyone has done something similar?


Thanks,

Andreas



Modbus TCPsunspec
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2 Answers
thomas-pv avatar image
thomas-pv answered ·

Modbus is not stable on Hoymiles

but you can use modbus rtu

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thomas-pv avatar image
thomas-pv answered ·

the sunspec protocol on hoymiles HM series is implemented only via rs485 and not via tcp.

Via tcp you can only query the tcp modbus register and not the sunspec register.

I killed two dtu pro by this way (modbus tcp). I used fhem (ModbusAttr)
with poll intervall of 10 seconds to query the power of 4 HM1500 with 4 x 4 PV panels. The dtu pro's died at night. The first after 5 days. The second after 2 days, They weren't not recoverable and became replaced.

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Modbus TCP Basics

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