IBM CTI 2572 manual TCP/IP Overview, TCP/IP Components

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CHAPTER 5. TCP/IP OVERVIEW

5.1 TCP/IP Components

TCP/IP consists of a hierarchy of related protocols. Upper level protocols are encapsulated in the data structure of lower level protocols.

Figure 11 TCP/IP Data Encapsulation

In a typical application using the 2572, the host computer application sends PLC commands via either TCP (Transmission Control Protocol) or UDP (User Datagram Protocol) services. TCP is used if connection-oriented communications is desired; UDP is used for connectionless communications. The TCP segment or UDP datagram is placed in an IP (Internet Protocol) datagram which is then sent to a 2572 over the network. The receiving 2572 removes the TCP (or UDP) packet from the IP datagram, removes the PLC command from the TCP (or UDP) packet, and transfers the PLC command to the PLC processor. Responses from the PLC are processed in a similar manner.

CTI 2572 Technical Overview Manual

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Contents Ethernet TCP/IP Adapter Module Technical Overview Page Document Disclaimer Statement Page Preface Page Table of Contents Page 802.3 Frame w/ Snap Header 10Base5 Thick Coax TopologyPage Description IntroductionSerial Redirect Server ModeClient Mode 2572 FunctionsMaster/Slave vs. Local Area Networks Local Area Network OverviewToken Ring Topology Ieee 802.5 Token-RingEthernet Topology Coax Ethernet and IeeeFuture Technologies Ieee 802.4 Token BusSummary Page ISO Reference Model Ethernet OverviewEthernet Topologies and Media Physical Layer 10BaseT Unshielded Twisted Pair UTP Bridges Foirl Fiber OpticEthernet Protocol Data Link Layer Mixed MediaEthernet Version 2 and Ieee 802.3 Packet Ethernet Version 2 standard defines the packet as follows Requirement for Higher Level Protocols Ethernet AddressesPage Connectionless vs. Connection Oriented Protocols Network ProtocolsConnectionless Protocols Common LAN Protocols Connection-Oriented ProtocolsIPX/SPX Page TCP/IP Components TCP/IP OverviewIP Address Internet ProtocolSubnet Address Mask Internet Control Message Protocol Icmp Address Resolution Protocol ARPUser Datagram Protocol UDP Connection-Oriented Communications That other network nodes can accessTransmission Control Protocol TCP Stream OrientationTCP Segment Reliable Data Transfer2572 TCP/IP Support Berkeley SocketsPage Non Intelligent Terminal Protocol PLC Command InterfaceTask Codes