wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

56-4 Industrial Communication Systems
Client
e.g., Web browser
Client layer
Documents
Server layer
Server
e.g., Web server
Data layer
Server
Data server
Data
FIGURE 56.3
Three-tier architecture.
Client
e.g., Web browser
Client layer
Documents
Server layer
Server
e.g., Web server
Application layer
Application
logic
Server
Application server
Data layer
Server
Data server
Data
FIGURE 56.4
Multitier architecture.
56.3.1 transport and Communication Related Technologies
The transport and communication related technologies cover well-known application protocol definitions
for a wide variety of Internet technologies. They include specific technologies for use in message-related
applications, like Simple Mail Transfer Protocol (SMTP) [SMTP82], Post Office Protocol
(POP) [POP94], Internet Message Access Protocol (IMAP) [IMAP03], and Network News Transfer
Protocol (NNTP) [NNTP06]. Typically, e-mail applications use these protocols in order to access
messages.
Within the Industrial Internet, this type of message transfer can be used to asynchronously transfer
data between applications, mostly in the upper layers of the automation pyramid (see Chapter 13),
mainly in Manufacturing Execution Systems (MES) layer and in Enterprise Resource Planning (ERP)
layer. It is, for example, possible to use such protocols and application to inform MES or ERP functions
© 2011 by Taylor and Francis Group, LLC