Mitsubishi Electric FX3U-ENET-ADP, Руководство пользователя

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1 Introduction
1.1 Outline
14
FX
3U
-ENET-ADP User's Manual
1.1.2 Features of the Ethernet adapter
The Ethernet adapter has the following features.
1) Users can read and write data and programs from/to the PLC using MELSOFT products such as GX
Works2 within the company LAN, etc.
2) Users can develop custom software to communicate with the PLC by using MC (MELSEC
Communication) protocol (A-compatible 1E frame subset, for details, refer to user's manual). (TCP/IP or
UDP/IP)
3) The FX
3U
-ENET-ADP can be connected directly (simple connection) to GX Works2 with only one
Ethernet cable without using the hub.
4) Users can search "FX
3U
-ENET-ADP + Main unit" connected in the network using the find CPU function of
GX Works2.
5) The FX
3U
-ENET-ADP can automatically set the time of the main unit using the time setting function.
6) The FX
3U
-ENET-ADP parameters can be set easily using GX Works2.
7) The diagnostic functions of GX Works2 enables easy diagnostics and troubleshooting of the FX
3U
-ENET-
ADP.
1.1.3 Ethernet related term
1) TCP (Transmission Control Protocol)
This protocol guarantees data credibility and reliability in communication between a personal computer/
work station and PLC that are connected via network, and provides the following functions:
- Creates a logical connection by establishing a connection (logical line) as if a dedicated line was
created between external devices.
- Up to 4 connections can be established and used at the same time in the Ethernet adapter.
- Data reliability is maintained by sequence control using the sequence numbers, the data
retransmission function and check sum.
- Communication data flow can be controlled by Windows operations.
2) UDP (User Datagram Protocol)
This protocol may not guarantee data credibility or reliability in communication between a personal
computer/work station and PLC that are connected via network. Thus, even if the data does not reach the
target node, it will not be retransmitted.
- Because it is connectionless, communication efficiency is much improved than TCP/IP.
- A check sum is used to increase the reliability of the communication data.
When greater reliability must be maintained, a user application or TCP should be used for the retrying
operation.
3) IP (Internet Protocol)
- Communication data is sent and received in datagram format.
- Communication data can be divided and reassembled.
- Routing option is not supported.
4) ARP (Address Resolution Protocol)
- This protocol is used to get the Ethernet physical addresses from the IP addresses.
5) ICMP (Internet Control Message Protocol)
- This protocol is used to exchange errors which occur on an IP network and various information related
to the network.
- Provides a function to transmit IP error messages.
- Refer to Appendix E-6 for information regarding the types of ICMP supported.