Toshiba V Series, User Manual

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Ethernet module User’s Manual
Chapter 1 Ethernet Module (EN311) Overview
1
1.6 Software Configuration
The EN311 transmission functions (computer link protocol transmission, PC link protocol
transmission, and socket interface transmission) are implemented with the software
configuration shown in the following figure.
Figure 1-10 Software Configuration
(1) TCP (Transmission Control Protocol)
Before transferring data with the remote node, a connection (virtual communication
circuit) is first established and then data is transferred. Packet order control,
retransmission, flow control, and other techniques guarantee transmission reliability.
The EN311 supports the following functions:
• Response bit (ACK)
• Synchronized bit (SYN)
• Fin bit (FIN)
• Retransferring
• Window (flow) control --- Some functions have limitations.
• Segment division
• Reporting of the maximum receivable segment length
• Push bit(PSH)
When EN311 transmits data, a PSH bit is always OFF.
S controller user program
USEND_T
／
URCV_T
function block
S controller firmware
Computer link/socket interface
G3 bus
Module interface
UDP TCP
IP ARP ICMP EN311
CSMA/CD
10BASE5 10BASE2
S controller