Does HA and Sigenergy device need to be on the same subnet?

[DoctorWkt]

At home I have a three private subnets, 10.10.1.0/24, 10.10.2.0/24 and 10.10.3.0/24. The HA device is on network 1, my Sigenstor battery + inverter are on network 3. WIll Sigenergy-Local-Modbus work through the intermediate local routers, or does the HA device need to be on network 3 as well? Thanks

P.S. I can telnet to the Sigenstor (IP 10.10.3.59 port 502) and get a TCP connection, so I think the Modbus is enabled.

[Roving-Ronin]

8 subnets / VLANs here and HA on one and Sigenergy (and 100 odd other IoT Devices on Ethernet and WiFi) all work fine together.

[DoctorWkt]

Thanks. I can telnet to the 502 port at 10.10.3.59 but when I try to configure the Sigenergy plant with the same IP address, after about ten seconds I get "Couldn't connect".

[StroppyOz]

Depending on how you've set your vlans up, you may need to make a route for HA to communicate to the Sigen. Get Outlook for Android<https://aka.ms/AAb9ysg>

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________________________________ From: Warren ***@***.***> Sent: Tuesday, October 7, 2025 1:40:57 PM To: TypQxQ/Sigenergy-Local-Modbus ***@***.***> Cc: Subscribed ***@***.***> Subject: Re: [TypQxQ/Sigenergy-Local-Modbus] Does HA and Sigenergy device need to be on the same subnet? (Discussion #233) Thanks. I can telnet to the 502 port at 10.10.3.59 but when I try to configure the Sigenergy plant with the same IP address, after about ten seconds I get "Couldn't connect". — Reply to this email directly, view it on GitHub<#233 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/BPOKID2MHABOY5Q5ZCA4W433WMR3TAVCNFSM6AAAAACIOW36GWVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTINRRGA2TOMQ>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[DoctorWkt]

Thanks. I can telnet to the Sigenergy from the HA device:

➜  ~ telnet 10.10.3.59 502
Connected to 10.10.3.59

I used tcpdump to capture the Modbus traffic. I can see the TCP handshake and several queries from the HA device. The Sigenergy system responds to all queries with something like this:

Modbus/TCP
    Transaction Identifier: 1
    Protocol Identifier: 0
    Length: 3
    Unit Identifier: 1
Function 4:  Read Input Registers.  Exception: Illegal data address
    .000 0100 = Function Code: Read Input Registers (4)
    Exception Code: Illegal data address (2)
Modbus/TCP
    Transaction Identifier: 1
    Protocol Identifier: 0
    Length: 3
    Unit Identifier: 1
Function 4:  Read Input Registers.  Exception: Illegal data address
    .000 0100 = Function Code: Read Input Registers (4)
    Exception Code: Illegal data address (2)

I am using 1 for the inverter slave id. Thanks in advance for any ideas!

[DoctorWkt]

Update: I moved my HA device from my 10.10.1.0/24 subnet to the 10.10.3.0/24 subnet, where the Sigenstor inverter is. Now HA can talk to the Modbus port and get data from the inverter. So, at least for me, the HA device has to be on the same subnet as the inverter.