scope:

The Vnet/IP is designed for highly reliable real-time communication, and applies to the operation of process control systems. The process control system consists of many controllers, human-machine interfaces, process monitors, and gateways to external networks which are connected to Ethernet-based IP networks. The data transfer between these devices is performed by peer-to-peer or multicast communication. It is required that the process control system responds within a deterministic time. At the same time, it is also required that multi-vendor's multi-devices can be connected to the same IP network. For example, the process control system shall handle operational signals for the actuator within a determined time and needs to communicate with other devices connected to Ethernet-based IP networks to exchange non-realtime information such as files and images. The Vnet/IP realizes these two conflicting requirements on the same network using a unique technology as described in this PAS. This PAS describes the communication profile of the whole Vnet/IP, services of each layer and the specifications of the protocols for each layer.