How can I operate several charging stations behind a router?

The setting-up of several charging stations at one site may lead to a compensation of costs, if common requirements can be divided up between the different stations. This concerns in particular the data cable for the connection of the charging stations to the be.ENERGISED back-end system.

You can group together at one location several charging stations on a communication link. This requires the installation of a router that takes over the central communication interface. Generally, this requires of course charging stations, which can subsequently be cross-linked with Ethernet cables.

In the networking of communication-enabled charging stations via a central router and a downstream Ethernet connection, you need to consider that an appropriate configuration of the router is required based on the SOAP (Simple Object Access Protocol) protocol in OCPP 1.5 to make incoming data connections possible.

This means that so-called NAT Forwarding must be configured in the router. If we look at a configuration example from one router and five downstream charging columns, this results in the following configuration requirements. The router is connected to the Internet with a SIM card or a DSL line and displays the central communication point. The router will create a local area network in the district 192.168.1.0/24, thus providing the charging stations with the following available IP addresses:

• Charging station 1: 192.168.0.11
• Charging station 2: 192.168.0.12
• Charging station 3: 192.168.0.13
• Charging station 4: 192.168.0.14
• Charging station 5: 192.168.0.15

With this configuration, the charging stations are already able to send messages to the back-end system.

For the back-end system to be able to transmit control commands to the charging station, the so-called NAT port forwarding must be configured in the router. This can be found depending on the router in the configuration area “ IP router “,” Network “or ” NAT “. Please consult, your router manual to see how to configure port forwarding.

Next you must configure the port forwarding in the router:

• Port forwarding 8081 to IP 192.168.0.11:80
• Port forwarding 8082 to IP 192.168.0.12:80
• Port forwarding 8083 to IP 192.168.0.13:80
• Port forwarding 8084 to IP 192.168.0.14:80
• Port forwarding 8085 to IP 192.168.0.15:80

You now still need to configure on the charger the WS-Addressing, this denotes the public IP address as well as the public port which the charging station transmits as identification to the back-end system. Please enter each public IP address of the router as well as the respectively configured forwarding port on the router:

• Charging station 1: Port 8081
• Charging station 2: Port 8082
• Charging station 3: Port 8083
• Charging station 4: Port 8084
• Charging station 5: Port 8085

If your charging station does not support the configuration of dynamic WS-Addressing values, you can also configure the OCPP endpoints yourself in the back end on the respective station data sheet of the station under the menu item Edit/communication link with the named configuration data and deactivate the automatic IP recognition.