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1. Overview of Vnet/IP

1-2

TI 30A10A05-01E

1.1 Vnet/IP Features

Vnet/IPisaprocessautomationcontrolnetworkthatisbasedongigabitEthernet.Ithas

thefeaturesthatareimportantforastableplantoperation,namelyhighreliability,and

real-timeresponse.Italsoprovidessecurityagainstthreatsfromanexternalnetwork,

such as cyber attacks.

Vnet/IP connects the devices that make up the CENTUM and ProSafe-RS systems. It

allowstheexchangeofcontroldataamongthesedevices.Vnet/IPcanalsoconnectto

othersystemsthatuseVnetorVLnetastheircontrolnetworkbyusingaVnetrouter.

You can use network devices such as Layer 2 Switch (L2SW) or Layer 3 Switch (L3SW),

andtransmissionmediasuchasUTPcablesoropticalbercablestosetupVnet/IP.

Vnet/IP is a control network that complies with the international standard (IEC 61784-2

Ed.2.0) and conforms to IEEE 802.3 and UDP/IP.

n Highreliability

Vnet/IP is a control network with dual redundant buses and consists of independent subnets, bus

1 and bus 2. The control communication is usually performed by using bus 1. However, when

a problem occurs in bus 1, the path switches immediately and automatically so that the control

communication is performed by using bus 2.

n Real-time response

Vnet/IP implements a dedicated protocol for performing high-quality communication on UDP/IP,

which is a protocol that is suitable for real-time communication.

The transmission scheduling function prevents transmission delays and packet loss by stopping

packets from being accumulated. Real-time response is achieved by prioritizing among the

di󰀨erent communication types.

n Security

Vnet/IP takes security into account. It performs authentication by using a shared secret key that

is updated periodically to prevent cyber attacks such as data eavesdropping, falsication, and

spoong.

SEE

ALSO

For more information about Vnet/IP security features, refer to the following.

“Security Standard of System Product” (TI 30A10A20-01E)

In this document, we recommend that you perform non-control communication, which is

information communication, on an information network other than Vnet/IP. If the information

network is not used but Vnet/IP is used for both control communication and information

communication, refer to the conditions described in Chapter 1.6 of this document

Aug.19,2011-01

YOKOGAWA Vnet/IP User Manual

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