Download Quest Controls BACnet T-Stat Technical data

Fieldbus Communication
ETHERNET
• 175
data and the resultant increase in processing speed.
Many programs use both protocols. Important status information is
sent via the reliable TCP connection, while the main stream of data
is sent via UDP.
(3)
TCP, UDP
(2)
IP
(1)
ETHERNET
(physical interface, CSMA/CD)
(4) Management, Diagnostic and Application Protocols:
CIP application objects library
CIP data management services
(explicit messages, I/O messages)
CIP message routing, connection
management
Encapsulation
protocol
...
(3)
TCP, UDP
(2)
IP
(1)
ETHERNET
(physical interface, CSMA/CD)
WAGO-I/O-SYSTEM 750
BACnet/IP Controller
ETHERNET/IP
...
CIP
Application device profiles
(e.g. positioning controllers, semiconductors, pneumatic valves)
MODBUS
WWW browser
HTTP
(4)
SMTP
Mail client
Positioned above the TCP/IP stack or UDP/IP layer are correspondingly implemented management, diagnostic and application protocols that provide services that are appropriate for the application. For the management and diagnostic, these are, for example, SMTP (Simple Mail Transport Protocol) for emails, HTTP (Hypertext Transport Protocol) for www browsers and some others.
In this example, the protocols MODBUS/TCP (UDP) and EtherNet/IP are implemented for use in industrial data communication.
Here the MODBUS protocol is also positioned directly above TCP (UDP)/IP;
EtherNet/IP, on the other hand, basically consists of the protocol layers
ETHERNET, TCP and IP with an encapsulation protocol positioned above it.
This serves as interface to CIP (Control and Information Protocol).
DeviceNet uses CIP in the same way as EtherNet/IP. Applications with DeviceNet device profiles can therefore be very simply transferred to
EtherNet/IP.