How to connect with PLC and EasyAccess using only one Ethernet port?

How to connect with PLC and EasyAccess using only one Ethernet port?
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I have an HMI eMT-3150A that is connected to a PLC by its single Ethernet port. Can I use the same port connected to an Ethernet switch to also connect to the internet for Easy Access 2.0? If so, what would be any requirements need of the router? Thanks


Easy Access, MT8051iE, MT8071iE, Codesys, LAN 2, LAN 1, LAN1, LAN2

It is possible. What you will have to do is to configure the gateway IP of your router to match the subnet of the EMT3150A and the PLC.
For example,
HMI’s IP -
Configure Gateway’s IP to or other appropriate 192.168.2.x.
By default the DHCP is enabled in a router.


From what my customer is telling me, their router setup is similar to my home setup. Their internet port IP is obtained dynamically from the ISP (see pic 1) and their router “LAN” setting is configured for DHCP with a Starting / Stopping IP address. You mention that I must change the router’s Gateway IP to be the same subnet as the PLC & HMI but according to picture 1 this would require the Internet Port IP to be switched to STATIC (at least on my home router) in order to change the gateway IP and since the service provided to the location is DYNAMIC IP I would say that this is not currently possible. Can we not change the gateway IP but rather make the router’s LAN DHCP Server addresses to be the same subnet mask as the PLC & HMI and start with an IP higher than the fixed IP that we assign to the PLC (to avoid conflict)? Sorry, but I only have limited knowledge of network topology and rely on the experts to point me in the right direction,thank you…

You don’t need to change the settings within the “Internet IP address”.
Go to the router’s LAN section and configure the IP address to be the same subnet mask as the PLC & HMI . For example,

Once finished, there shall be a sub menu called “DHCP Server”. It allows you to determine which addresses are DHCP IP addresses. For example,

Great and thanks once again!

Note: For anyone else that may have questions related to this topic, here are some examples.

HMI + Codesys:

HMI with 1 x Ethernet port: