- •Important Comments
- •Legal Principles
- •Copyright
- •Personnel Qualification
- •Intended Use
- •Symbols
- •Font Conventions
- •Number Notation
- •Scope
- •Important Comments for Starting up
- •Abbreviation
- •The WAGO-I/O-SYSTEM 750
- •Technical Data
- •Manufacturing Number
- •Storage, Assembly and Transport
- •Mechanical Setup
- •Installation Position
- •Total Expansion
- •Assembly onto Carrier Rail
- •Carrier rail properties
- •WAGO DIN Rail
- •Spacing
- •Plugging and Removal of the Components
- •Assembly Sequence
- •Internal Bus / Data Contacts
- •Power Contacts
- •Wire connection
- •Power Supply
- •Isolation
- •System Supply
- •Connection
- •Alignment
- •Field Supply
- •Connection
- •Fusing
- •Supplementary power supply regulations
- •Supply example
- •Power Supply Unit
- •Grounding
- •Grounding the DIN Rail
- •Framework Assembly
- •Insulated Assembly
- •Grounding Function
- •Grounding Protection
- •Shielding (Screening)
- •General
- •Bus Conductors
- •Signal Conductors
- •WAGO Shield (Screen) Connecting System
- •Assembly Guidelines / Standards
- •Fieldbus Controller
- •Fieldbus Controller 750-841
- •Description
- •Hardware
- •View
- •Device Supply
- •Fieldbus Connection
- •Display Elements
- •Configuration and Programming Interface
- •Operating Mode Switch
- •Hardware Address (MAC-ID)
- •Operating System
- •Start-up
- •PLC Cycle
- •Process Image
- •Example of a Process Input Image
- •Example of a Process Output Image
- •Fieldbus specific Process Data Architecture for MODBUS/TCP
- •Digital Input Modules
- •Digital Output Modules
- •Analog Input Modules
- •Analog Output Modules
- •Specialty Modules
- •Data Exchange
- •Memory Areas
- •Addressing
- •Addressing the I/O Modules
- •Address Range
- •Absolute Addresses
- •Data Exchange between MODBUS TCP Master and I/O Modules
- •Data Exchange between Ethernet IP Master and I/O Modules
- •Data Exchange between PLC Functionality (CPU) and I/O Modules
- •Data Exchange between Master and PLC Functionality (CPU)
- •Example MODBUS TCP Master and PLC functionality (CPU)
- •Comparison of MODBUS TCP Addresses and IEC 61131-3 Addresses
- •Starting up an ETHERNET TCP/IP fieldbus node
- •Connecting PC and Fieldbus Node
- •Determining IP Addresses
- •Allocating the IP Address to the Fieldbus Node
- •Testing the Function of the Fieldbus Node
- •Deactivating the BootP Protocol
- •Programming the PFC with WAGO-I/O-PRO CAA
- •WAGO-I/O-PRO CAA library elements for ETHERNET
- •IEC 61131-3-Program transfer
- •Transmission via the Serial Interface
- •Transmission by the Fieldbus
- •Information on the web-based management system
- •LED Display
- •Blink code
- •Fieldbus status
- •Node status
- •Fault Message via Blink Code from the I/O-LED
- •Supply voltage status
- •Fault behavior
- •Fieldbus failure
- •Internal bus fault
- •Technical Data
- •I/O Modules
- •General
- •Digital Input Modules
- •Digital Output Modules
- •Analog Intput Modules
- •Analog Output Modules
- •Counter Modules
- •ETHERNET
- •General
- •Network Architecture – Principles and Regulations
- •Transmission Media
- •Network Topologies
- •Coupler Modules
- •Important Terms
- •Network Communication
- •Protocol layer model
- •Communication Protocols
- •ETHERNET
- •Channel access method
- •IP-Protocol
- •IP Multicast
- •TCP Protocol
- •Application Protocols
- •MODBUS
- •Ethernet/IP
- •BootP (Bootstrap Protocol)
- •HTTP (HyperText Transfer Protocol)
- •DHCP (Dynamic Host Configuration Protocol)
- •DNS (Domain Name Systems)
- •SNTP-Client (Simple Network Time Protocol)
- •FTP-Server (File Transfer Protocol)
- •SNMP V1 (Simple Network Management Protocol)
- •Configuration of SNMP
- •Description of MIB II
- •IpNetToMediaTable
- •Traps
- •SMTP (Simple Mail Transfer Protocol)
- •MODBUS Functions
- •General
- •Use of the MODBUS Functions
- •Description of the MODBUS Functions
- •Function Code FC1 (Read Coils)
- •Function Code FC2 (Read Input Discretes)
- •Function Code FC3 (Read multiple registers)
- •Function code FC4 (Read input registers)
- •Function Code FC5 (Write Coil)
- •Function Code FC6 (Write single register)
- •Function Code FC11 (Get comm event counter)
- •Function Code FC15 (Force Multiple Coils)
- •Function Code FC16 (Write multiple registers)
- •Function Code FC22 (Mask Write Register)
- •Function Code FC23 (Read/Write multiple registers)
- •MODBUS Register Mapping
- •Internal Variables
- •Description of the internal variables
- •Watchdog (Fieldbus failure)
- •Watchdog Register:
- •Diagnostic Functions
- •Configuration Functions
- •Firmware Information
- •Constant Registers
- •Ethernet/IP (Ethernet/Industrial Protocol)
- •General
- •Characteristics of the Ethernet/IP Protocol Software
- •Object model
- •General
- •Classes
- •CIP Common Classes
- •Static Assembly Instances
- •Application examples
- •Test of MODBUS protocol and fieldbus nodes
- •Visualization and control using SCADA software
- •Use in Hazardous Environments
- •Foreword
- •Protective measures
- •Classification meeting CENELEC and IEC
- •Divisions
- •Explosion protection group
- •Unit categories
- •Temperature classes
- •Types of ignition protection
- •Classifications meeting the NEC 500
- •Divisions
- •Explosion protection groups
- •Temperature classes
- •Identification
- •For Europe
- •For America
- •Installation regulations
ETHERNET • 121
Network Communication
5.3.2.1 ETHERNET
ETHERNET address (MAC-ID)
Each WAGO ETHERNET fieldbus coupler is provided from the factory with a unique and internationally unambiguous physical ETHERNET address, also referred to as MAC-ID (Media Access Control Identity). This can be used by the network operating system for addressing on a hardware level.
The address has a fixed length of 6 Bytes (48 Bit) and contains the address type, the manufacturer’s ID, and the serial number.
Examples for the MAC-ID of a WAGO ETHERNET fieldbus coupler (hexadecimal): 00H-30H-DEH-00H-00H-01H.
ETHERNET does not allow addressing of different networks.
If an ETHERNET network is to be connected to other networks, higherranking protocols have to be used.
Note
If you wish to connect one or more data networks, routers have to be used.
ETHERNET Packet
The datagrams exchanged on the transmission medium are called “ETHERNET packets” or just “packets”. Transmission is connectionless; i.e. the sender does not receive any feedback from the receiver. The data used is packed in an address information frame. The following figure shows the structure of such a packet.
Preamble |
ETHERNET-Header |
ETHERNET_Data |
Check sum |
|
|
|
|
8 Byte |
14 Byte |
46-1500 Byte |
4 Byte |
|
|
|
|
Fig. 5-9: ETHERNET-Packet |
|
|
|
The preamble serves as a synchronization between the transmitting station and the receiving station. The ETHERNET header contains the MAC addresses of the transmitter and the receiver, and a type field.
The type field is used to identify the following protocol by way of unambiguous coding (e.g., 0800hex = Internet Protocol).
5.3.3 Channel access method
In the ETHERNET Standard, the fieldbus node accesses the bus using
CSMA/CD (Carrier Sense Multiple Access/ Collision Detection).
• |
Carrier Sense: |
The transmitter senses the bus. |
• |
Multiple Access: |
Several transmitters can access the bus. |
• Collision Detection: A collision is detected.
Each station can send a message once it has established that the transmission medium is free. If collisions of data packets occur due to several stations transmitting simultaneously, CSMA/CD ensures that these are detected and the data transmission is repeated.
However, this does not make data transmission reliable enough for industrial requirements. To ensure that communication and data transmission via ETHERNET is reliable, various communication protocols are required.
WAGO-I/O-SYSTEM 750 ETHERNET TCP/IP