In order to use a charging station for electric vehicles with a backend system such as "be.ENERGISED", the charging station must meet the basic requirements for operation:
- The charging station must have a communication unit (GSM)
- Support of a backend connection based on OCPP in versions 1.5 or 1.6, based on SOAP or JSON
- Provision of authorization mechanisms for the unique identification of a user, based on ISO 14443 or compatible requirements
- Transmission of counter values (minimum requirement: Wh, optional voltage or temperature data), during an active charging process counter values must be documented for the respective charging process
- Ability to start a charging process via a remote interface (RemoteStartTransaction)
- The charging station must support remote parameterization (ChangeConfiguration) as well as the query of diagnostic data (GetDiagnostics).
Requirement for charging station billing capability
- If the charging station is used for kWh-based billing, the charging station must support at least OCPP version 1.6 and the transmission of signed meter data. The electricity meter must meet the requirements of the calibration law.
Depending on the manufacturer and degree of implementation, the functionality of a charging station may vary. However, from our point of view, the basic functions required for connecting with backend systems are currently sufficiently implemented by most well-known manufacturers. The backend software of has·to·be »be.ENERGISED« has been tested and certified with many manufacturers in the European market environment.
On our product list (available on request) the supported manufacturers are regularly updated and listed. Due to the rapid development of the market, this list is continuously expanded and supplemented. However, the fact that a charging station has a communication capability does not mean that the connection will work immediately. It is necessary to technically establish the communication between the charging station and the central administration system.
Therefore, you have multitude options, which can be used differently depending on the number of charging stations planned, the flexibility of your own IT structure or the required security requirements:
- Connection via a M2M network operated by you with an Open-VPN tunnel
- Connection of charging stations with SIM cards provided by has·to·be
- Connection of charging stations via OpenVPN certificates
Basically, these methods represent the technical basis for networking charging stations in an IT infrastructure. In the following, different technical possibilities will be described in detail.
Connection via M2M network
An M2M (machine-to-machine) network is a SIM card-based communication network operated by your mobile operator. To set up the communication network, special M2M data cards are used, which are technically comparable to standard SIM cards, but do not allow any direct communication to the Internet. In an M2M network all SIM cards receive an internal IP address and thus communication between the individual charging stations or the central server system is possible.
This constellation enables you to operate an IT infrastructure with little effort. You can also include service technicians and maintenance personnel in this infrastructure, so that ordinary maintenance and service of charging stations can be carried out remotely. Normally, there are no firewall connections in this configuration that block communications from being established. Within this secure network, you have the option of establishing connections freely and without barriers and adapting the routing definitions to your requirements.
If you already operate an M2M infrastructure in your IT landscape, it can usually be extended easily so charging stations can be integrated quickly. You should provide your own IP number range. That way you can use simple routing configurations to grant external service technicians restricted access to certain charging stations. The connection of an existing M2M infrastructure to backend systems is usually done by establishing an OpenVPN or IpSec data connection between the central system of your M2M infrastructure and the server system of the backend system. This means that the entire IT infrastructure can be accessed via a single encrypted connection.
If your company does not yet have its own M2M infrastructure, you can entrust any mobile phone provider with the construction and operation of an M2M infrastructure. Alternatively, you can also use the managed M2M infrastructure from has·to·be. You will receive M2M SIM cards activated by has·to·be for the best network in your region. The SIM cards are completely managed and monitored by has·to·be. The required management is carried out by has·to·be.
There are also various technical options for the integration of your charging stations via SIM cards:
If your charging station already has a SIM card slot, you just insert the SIM card into the charging station and perform the necessary configuration at the charging station. The charging station receives an IP address after configuration and the connection to the server system should be established immediately after connecting to the M2M network.
Requirements for connection via GSM
- SIM slot for a SIM card in normal or Micro-SIM format
- authorization via PAP/CHAP for connection to the has·to·be APN
- The charging station must be able to establish a connection and hold it permanently
However, if your charging station does not have its own SIM slot, it is possible to install a UMTS router to the charging station. You can insert the SIM card into the UMTS router and configure the connection on this router system. The UMTS router serves as a gateway for establishing the connection. The necessary port forwarding to the charging station must be configured via the router. It is recommended to configure the charging station as "DMZ" (demilitarized zone) on the router.
In general, we do not recommend the usage of standard SIM cards or prepaid data cards, as these SIM cards usually do not allow a return channel from the server system to the charging station. When using standard SIM cards, it is therefore likely that a remote control of the charging station cannot be achieved or that you will have to use your own VPN certificates in addition to the SIM card in order to establish a connection. This requirement reaches a high level of complexity of your infrastructure which we do not recommend.
Connection via OpenVPN certificates
Alternatively, to the options of connections mentioned above, the integration of charging stations into the IT landscape can also be performed by using VPN certificates on the charging station. However, this requires the operation of a central VPN server infrastructure, which can be carried out either by you or by a VPN service provider.
Has·to·be also offers the operation of the Open VPN infrastructure as a managed service for this use case. You will receive personally issued VPN certificates for your charging stations, which allow direct access to the VPN infrastructure.
In the case of integration via VPN, the charging stations are integrated via Open VPN certificates, which are issued centrally by the operator of the VPN infrastructure. Also in this constellation the integration of the VPN certificates can take place directly on the charging station - if it supports the integration of VPN certificates - or you install a router system to the charging station, which ensures the establishment of the VPN connection to your IT infrastructure.
Requirements for connection via Ethernet
- The charging station must allow a connection via OpenVPN certificates to enable an encrypted connection
- If the charging station uses a router for connection control, port forwarding to the station must be possible