Common Industrial Protocol (Ciptm) - Scaime eNod4-F ETHERNET Software User Manual

By using TCP/IP, EtherNet/IP is able to send explicit messages, which are used to perform client-server type
transactions between nodes. Nodes must interpret each message, execute the requested task and generate
responses. Uploading and downloading of configuration data like setpoints and applicative parameters uses explicit
(or Class 3) messaging.
TCP is connection-oriented and use well known TCP port number 44818 (0xAF12) for EtherNet/IP.
For real-time messaging, EtherNet/IP also employs UDP over IP, which allows messages to be unicast (one to one) or
multicast (one to a group of destination addresses) in a producer-consumer model. This is how CIP™ I/O data
transfers called implicit (or Class1) messaging is sent on EtherNet/IP. With implicit messaging, the data field contains
no protocol information, only real-time I/O data. Since the meaning of the data is pre-defined at the time the
connection is established, processing time is minimized during runtime. UDP is connectionless and makes no
guarantee that data will get from one device to another; however, UDP messages are smaller and can be processed
more quickly than explicit messages. As a result, EtherNet/IP uses UDP/IP to transport I/O messages that typically
contain time-critical control data. The CIP™ Connection mechanism provides timeout mechanisms that can detect
data delivery problems, a capability that is essential for reliable control system performance.
UDP port used is port 2222 (0x08AE).
The process of opening a connection is called Connection Origination, and the node that initiates the connection
establishment request is called a Connection Originator, or just an Originator (so called Scanner). Conversely, the
node that responds to the establishment request is called a Connection Target, or a Target (so called Adapter).

6.2.2 Common Industrial Protocol (CIPTM)

TM
Common Industrial Protocol (CIP ) has implementations based upon Ethernet with EtherNet/IP, but also through
TM TM
DeviceNet (CIP over CAN bus) and ControlNet (CIP over a dedicated network).
Most controllers (with appropriate network connections) can transfer data from one network type to the other,
leveraging existing installations, yet taking advantage of Ethernet.
CIP™ is an object oriented protocol. Each CIP™ object has attributes (data), services (commands) and behaviors
(reactions to events). Objects are also named classes. An object instance refers to one implementation of a class. Each
instance of a class has the same attributes, but its own particular set of attribute values.
We use attributes to refer to the data of an object. You use methods to operate on the data. Every attribute of an
object will have a corresponding method and you invoke a method by sending a service to it. Services are the
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