Annex D Requirements on Network Infrastructure of Components of a Vending Machine (Normative)

The communication infrastructure between the different OPC UA components is IP based, which enable all components to be installed as software components on a single hardware able to run the client/server applications using the localhost interface.

The addition of a component which is also a hardware part, require to add ethernet connections between the parts.

The hardware interface used by the Vending Machine components shall be 802.3 (either 10 or 100 (803.3u) or 1000BaseT (802.3ab)), using the standard RJ45 interface connector and the cables specified by IEEE 802.3.

Physically connecting more than two devices requires the addition of a hub or switch device; powered from the main power source inside the machine (see Annex C); to enable easy integration, the space for the Hub must be provided inside the Vending Machine enclosure.

A preferred solution will be each device has a couple of Ethernet ports with switch capabilities between the two ports; in this way adding a cable is the only needed addition to add any number of devices.

Device manufactures which can make their devices as combination of different components can use any way to connect their components, but finally has to provide an Ethernet interface towards with OPC UA protocol to connect to the outside word.

Given the system is IP based, other functions can run on the same interface. A good example is the need for external connectivity: if one the devices connected to the network has external connection capabilities, is can be useful to make these capabilities accessible to all other components: the needed information is the device IP address and a proper configuration of the bridge/router/gateway which enable the sharing of this interface. Even if this is not a requirement for this document, this capability is highly recommended; the major issue to solve is about the data transfer accounting when different actors are using the same communication channel.

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