question

peter-vddriessche avatar image
peter-vddriessche asked

How to use ModbusTCP over WAN

Hello, I have a CCGX and want to read registers remotely using Modbus. I can read registers when I am linked to the local modem using Wifi (I found the IP address to be used for the ModbusTCP message in the 'Settings/Ethernet' of the console).

But I also want to do it over the internet.

The CCGX is connected to the internet with a modem and I have enabled 'port forwarding' (of port 502 which we need) on the internet-modem.

But which IP address should I use to send the message?

Do I use the IP address of the internet modem? And what if that is not a fixed IP address?

The VRM portal has no problem with this (so even if the IP address changes, it manages to find it). Can I see the IP address somewhere in the VRM portal?

Thx

Peter

Modbus TCP
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2 Answers
trip-tracks avatar image
trip-tracks answered ·

You will need to use the public ip address (the private address is not visible outside your LAN)

You will need a static ip address or use a forwarder for your dynamic address from a service provider like noip (https://www.noip.com)




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sandebs answered ·

Hi Peter, did you find a solution to this problem?

I am trying to do the same thing in order to get access to an ESS at a remote location, so I am not connected to the LAN but want to connect over internet and communicate using modbusTCP.

How did you manage to read registers remotely?

Thank you

Sander

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Related Resources

Modbus TCP Basics