VPN - CE system access with upstream NAT router
If a router with NAT function is used in the network in which the Windows CE system is situated, port forwarding must be configured on the router for external access to the controller.
Structure
External queries to the router will be interpreted by the router and relayed to an internal host (the Windows CE system) in accordance with a configured port forwarding. In a port forwarding, an internal host is made externally available via a certain port.
In the case of our Windows CE system, for example, the following ports could be forwarded:
TwinCAT tcp/48898
CerHost tcp/987
For example:
An internal Windows CE system with the IP address 192.168.2.1 should be accessible through the Internet via Cerhost.
To do this, a port forwarding is configured on the router that maps TCP Port 987 to the internal IP address 192.168.2.1.
Setting up the Windows CE system
No settings need to be made in the Windows CE system. A connection just needs to be made to the router and the router used as a gateway.
Setting up the router
The router setup depends on the brand and type. Please refer to your router’s documentation regarding this point.
Connection to CE system
The external IP address of the NAT router must be used to connect TwinCAT or CerHost to the plc.