Software Settings
3.5
Global Data Configuration
At a Glance
Introduction
What's in this
Section?
This chapter contains a description about Global Data configuration.
This section contains the following topics:
Topic
Planning the Global Data (Publish / Subscribe) System
Quantum NOE Global Data Configuration
Page
38
42
37
Software Settings
Planning the Global Data (Publish / Subscribe) System
Overview
Global Data service is a real time Publisher/Subscriber mechanism providing the most efficient data exchange for PLC application coordination.
Devices supporting Global Data are arranged in a distribution group for the purpose of application variable exchange and synchronization. Each Global Data device can publish up to one network (application) variable and subscribe up to 64 network
(application) variables.
The Quantum NOE’s embedded Global Data Configuration Web page provides a configuration screen to determine which and how many application variables are exchanged with this service. After configuration, the exchanges between all stations belonging to the same distribution group are done automatically.
The Global Data service uses %MW (4x registers) for Global Data exchanges.
Key Features of
Global Data
The main features for Global Data are: l l l
One publisher and many subscribers
A device can publish one network variable of up to 512 %MW words (4x registers)
A device can subscribe of up to 64 network variables of up to 2048 %MW words l l l l
(4x registers)
A device subscribes to the complete network variable
One distribution group per network IP address
Application defined publication rate
Up to 64 Global Data Network variables (numbered from 1 to 64) can be part of the data distribution group l
A NOE has only one multicast address; consequently, it can only publish and subscribe inside the group l A device can participate in several distribution groups by using multiple NOEs in the rack
Global Data has an advantage over Client / Server services when more than one subscriber is receiving the same data since only one transaction is necessary for all l l subscribers to receive the data.
This advantage offers two benefits:
Reduce overall network traffic
Ensure tighter synchronization of multiple subscribers
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Software Settings
Planning Your
System
Configuration
The Global Data (Publish / Subscribe) utility is a powerful function incorporated into the NOE product line. Implementing Global Data requires a configuration that spans many PLCs throughout the system. Therefore, we recommend preplanning your installation before implementation. Work spent on preplanning saves time and money by reducing errors and unnecessary debugging time. Preplanning also serves as an aid to ensuring consistency throughout the system.
Go to paper before computer.
We offer the following table to help with your system planning. The table below is a graphic representation of a recommended configuration table for system planning, which we call the Global Data Planning Spreadsheet. You may create your own table using the format below or you may download a Microsoft Excel
TM
spreadsheet template which is available on the Schneider public Web site.
Here is the graphic representation of the Global Data Planning Spreadsheet.
Parameter
Checking
Variable ID
Symbol
1.
Length
(Registers)
Device Number Variable
Public.
Status
1
2
...
64
VALVE_STATUS
VALVE_CONTROL
PUMP_CONTROL
20
10
50
1
PUB
SUB
SUB
2
SUB
NONE
PUB
...
3
NONE
PUB
NONE
OK
OK
OK
Group IP Address
Multicast Filtering Enabled
Default 4x Address for Health
Distribution Period
Health Timeout
Data Zone
Device Publication Status:
Total Publication Size per Node:
Total Subscription Size per Node:
239.255.255.0
OFF
400100
10
1000
400200
OK
20
60
OK
50
20
OK
10
0
1. Entries or changes to the symbol (description) do NOT affect or change a variable or the system. The Symbol used in the Quantum product line has no relation to the Concept / Unity product line symbol.
39
Software Settings
Table of Global Data Limits
Parameter
Maximum number of publish variables per device
Limit
1
Maximum size for the publish variable
Maximum number of subscription variables per device 64
(63 if this device is publishing)
Maximum size for the subscripe variables per device
512 Registers = 512 Words (16 bits) =
1024 Bytes
2048 registers = 2048 Words (16 bits) =
4096 Bytes
Note: We recommend that you consider the following when planning.
l
10 to 20% Increase margin for growth
We suggest that you allow for a percentage increase in growth of any variable, l a 10 to 20% increase allowance should be sufficient.
Add at end
We recommend that you add variables at the end of the configuration because variables added at the end of the configuration do not affect the existing application address. Therefore, you avoid changing the existing addresses in your configuration, which can be a time consuming process.
Table of Global Data Planning Spreadsheet
Parameter
Parameter Checking
Variable Id
Symbol
Length Words (Registers)
Device Number
Variable Public. Status
Device Publication Status
Description
Reserved
Represents the Data ID on the NOE’s Global Data Configuration Web page
Symbolic name for Global Data exchange.
Length of Global Data information. Number of %MW words (4x registers).
Number of devices for the Global Data network. Of up to 64.
Automatic information of the correct publication status of the Global Data network.
Only by using the Microsoft Excel
TM
spreadsheet. Information per symbol.
Automatic information of the correct publication status of the Global Data network.
Only by using the Microsoft Excel
TM
spreadsheet. Information per device.
Total Publication Size per Node Publication size for the specific node. The maximum publication size is 512 words
(registers) per node
Total Subscription Size per
Node
Group IP Address Enabled
Subscription size for the specific node. The maximum subscription size is 2048 words (registers) per node
IP address for multicast networking. Identifies the stations distribution group. The address range is from 224.0.0.0 to 239.255.255.255
Multicast Filtering Enabled A check box for Ethernet switches that support multicast filtering.
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Parameter
Default Address for
Health%MW (4x register)
Distribution Period
Health Timeout
Data Zone
Software Settings
Description
%MW (4x register) address for the Health bits. This is the memory area where the
Health bits are stored. It has the size of 4 words (registers).
Is the minimum number of controller scan times before an update will occur.
Is the maximum time between received subscriptions before a subscription is declared unhealthy (faulty). The value is measured in milliseconds and can be set to a value that ranges from 50 through 1000 ms (increase in units of 50 ms)
The starting address for the data. This are the registers where the data information are stored.
41
Software Settings
Quantum NOE Global Data Configuration
Introduction
Global data configuration is carried out in the network configuration as well as the data editor.
The variables for the Publish/Subscribe procedure are configured in the data editor.
The screen shot shows the network configuration Global data configuration settings.
ETHERNET_1
Model Family
TCP/IP 10/100 Regular connection
Module IP Address
IP-Adresse
0 . 0 . 0 . 0
Subnetwork Mask
0 . 0 . 0 . 0
Modul Address
Rack Module
Gateway Address
0 . 0 . 0 . 0
Module Utilities
YES Access Control
YES
YES
I/O Scanning
Global Data
YES
YES
SNMP
Address Server
IP Configuration Access Control
Global data configuration
I/O Scanning
HealthTimeout 1000 ms
Global Data
SNMP Address Server
Group address 239 . 10 . 10 . 10
Bandwidth
Diistribution period 10 scan Group name plantgrp
Health bit block (%I / %WIW) %IW1
Multicast Filtering
Parameter
Health timeout
Group address
Distribution time
Group name
Status bit block
Multicast filtering
Parameter description
Description
After this time period has run out, the data received becomes invalid.
Class D Multicast IP address. All nodes in the global data procedure use the same Multicast address for distributing or receiving data. The address range is: 224.0.0.0 to
239.255.255.255.
Time after which the data is received or sent. Minimum scan time of the PLC.
Logical name. Defines the varibale allocation to different communication configurations in the variablen editor.
Address for retrieving the status information of the global data procedure.
Activates an Ethernet switch on connection that supports Multicast filtering.
42
Software Settings
The screen shot shows an image of the data editor.
Variables
Filter
DDT Types
Function Blocks DFB Types
Name
Name
VALVE_STATUS
VALVE_CONTROL
PUMP_STATUS
*
Type
ARRAY[0..19] OF Word
ARRAY[0..9] OF Word
ARRAY[0..99] OF Word
EDT
Address
%MW200
%MW220
%MW230
Global ...
PUB
SUB
SUB
DDT
Group plantgrp plantgrp plantgrp
IODDT
2
3
Enet ID
1
Parameter description
Parameter
Name
Type
Address
Enet
Group
Enet ID
Description
Variables ID
Variable type
Variable address
Type of Global Data Variable. Options: No/Publish/Subscribe
Group name for allocating the variables of the existing network description. When creating the different Ethernet networks, a logical connection is arranged here between the network and the variable declaration.
Ethernet ID. Representation of the administrative order.
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