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1.2 Overview of ET-LAN Unit Functions
1.2.1 Function Model
The functions of the ET-LAN unit are shown in the diagram below.
I/O and shared memory are used for the interface to the user program (CPU unit).
A maximum of eight simultaneous connections are possible for each of the computer link, data transfer,
and transparent communication functions.
The layers beneath the transport layer of the ET-LAN unit provide the following communication services.
TCP (Transmission Control Protocol):
TCP is a connection-based communication method which provides the virtual circuit. In the TCP
communication method, since communication services including re-transmission, sequence and flow
control for the communication data are provided, high communication reliability is guaranteed at the
protocol level.
UDP (User Datagram Protocol):
UDP is a connectionless communication method which provides only data communication in IP units. In
the UDP communication method, since no re-transmission, sequence, or flow control for the
communication data is provided, support at the application level is required to guarantee communication
reliability.
IP (Internet Protocol):
IP is used to transmit data in units of datagrams to partner node specified by an IP address. It provides
function such as the dividing and reassembling of communication data and communication services
between networks via a router.
ICMP (Internet Control Message Protocol):
ICMP is used to transmit the error message in the IP. The ET-LAN unit supports the echo replay option
only to the ping command.
ARP (Address Resolution Protocol):
ARP is used to transmit the Ethernet (physical) address, which is essential to Ethernet communications,
by specifying the IP address. When an ET-LAN unit accesses a station with unknown Ethernet address,
you only need to specify its IP address using the broadcast method.
AUI (Attachment Unit Interface
AUI is a transceiver cable that connects the ET-LAN unit with a transceiver.
Содержание FP2 ET-LAN
Страница 11: ...Chapter 1 Unit Functions and Restrictions ...
Страница 14: ...1 4 1 1 4 Connecting to a Network AFP2790 100BASE TX 10BASE T 10BASE5 AUI AFP27901 ...
Страница 24: ...1 14 ...
Страница 25: ...Chapter 2 Names and Functions of Parts ...
Страница 29: ...Chapter 3 Connection for LAN Cable ...
Страница 37: ...Chapter 4 Confirming the Design Contents ...
Страница 49: ...Chapter 5 Initialization Processing and Termination Processing ...
Страница 51: ...5 3 Operation of the ET LAN unit The relationship between initialization processing and open processing ...
Страница 68: ...5 20 ...
Страница 69: ...Chapter 6 Open Processing and Close Processing ...
Страница 71: ...6 3 Operation of the ET LAN unit The relationship between open processing and close processing ...
Страница 84: ...6 16 ...
Страница 85: ...Chapter 7 Computer Link Function ...
Страница 94: ...7 10 Program example ...
Страница 97: ...7 13 Example of communication data Same hierarchy communication ...
Страница 100: ...7 16 Example of communication data Other hierarchy communication ...
Страница 101: ...7 17 Other hierarchy communication for MEWTOCOL COM ...
Страница 102: ...7 18 ...
Страница 103: ...Chapter 8 Data Transfer Function ...
Страница 111: ...8 9 Program example ...
Страница 114: ...8 12 Example of communication data Same hierarchy communication ...
Страница 117: ...8 15 Example of communication data Other hierarchy communication ...
Страница 119: ...8 17 Other hierarchy communication for MEWTOCOL DAT ...
Страница 120: ...8 18 ...
Страница 121: ...Chapter 9 Transparent Communication Function ...
Страница 137: ...9 17 Program example ...
Страница 140: ...9 20 Reception processing After the following program has been run the received data is read from the receive buffer ...
Страница 141: ...9 21 9 5 3 Sample Program Reception to Transmission Program example for transmitting received data as it is ...
Страница 143: ...Chapter 10 Auto Connection ...
Страница 155: ...10 13 Case 1 Ladder program example ...
Страница 169: ...Chapter 11 E mail Function ...
Страница 200: ...11 32 ...
Страница 201: ...Chapter 12 Error Log Function ...
Страница 203: ...12 3 Latest log block area Log block reading processing area ...
Страница 219: ...Chapter 13 Troubleshooting ...
Страница 224: ...13 6 13 2 4 Troubleshooting Flowchart ...
Страница 225: ...13 7 ...
Страница 229: ...Chapter 14 MEWTOCOL Communication Procedure ...
Страница 241: ...14 13 WD Write data area This writes the contents of the data area To write the contents of DT LD and FL ...
Страница 242: ...14 14 To write to an index register ...
Страница 262: ...14 34 ...
Страница 263: ...Chapter 15 Specifications ...
Страница 292: ...15 30 15 6 ASCII Codes ...
Страница 293: ...15 31 15 7 Dimensions AFP2790 FP2 ET1 AFP27901 FP2 ET2 ...
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Страница 295: ...Chapter 16 Sample Program ...
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