Topic 3.3.1: Introduction
- Section Objectives
- Become familiar with Device Integration Objects, I/O Server and Data Access Server
- Overview of DI objects
- Become familiar with Device Integration Objects, I/O Server and Data Access Server
- Overview of DI objects
- Dynamic Data Exchange (DDE)
- Dynamic Data Exchange (DDE) is a communication protocol developed by Microsoft to allow applications in the Windows environment to send/receive data and instructions to/from each other. It implements a client-server relationship between two concurrently running applications.
- Wonderware SuiteLink
- Wonderware SuiteLink uses a TCP/IP-based protocol. SuiteLink is designed specifically to meet industrial needs, such as data integrity, high-throughput, and easier diagnostics. This protocol standard is supported for Windows 2000, Windows 2003 Server, and Windows XP.
- SuiteLink is Not a Replacement for DDE. Wonderware recommends that DDE be used for internal client communication, and SuiteLink for communication over the network.
- DDE and SuiteLink I/O Addressing
- DDE and SuiteLink identifies an element of data in an I/O data source program by using a three- part naming convention that includes the application name, topic name and item name. To obtain data from another application, the client program opens a communication channel to the server program by specifying these three items. Additionally, if the communication channel is between applications running in different computers, a node name must be specified too.
- Node: Name of the computer the I/O data source program or service is running on.(IP Number of respective System)
- Item: Name of the actual individual data point to be access once the communication channel is opened.
- Topic: It's an application-specific sub-group of data elements.
- Application: Name of the source program or service that provides I/O data to the client application. This is the name of the executable file without the extension.
- OPC
- Today the acronym OPC stands for Open Platform Communications.
- OPC is the interoperability standard for the secure and reliable exchange of data in the industrial automation space and in other industries. It is platform independent and ensures the seamless flow of information among devices from multiple vendors.
- The OPC client software is a program that connects to the hardware, such as an HMI, SCADA, PLC etc. The OPC client communicates with the OPC server to receive data or send commands to the hardware
Following OPC specifications are used in industries:
- OPC-DA (Data Access): Provides access to real-time data. We can query most recent values of temperature, pressure, density, acceleration, and other types of process control data from OPC-DA server.
- OPC-HDA (Historical Data Access): This is used to retrieve historical process data for analysis. This data is typically stored in files, databases or remote telemetry systems.
- OPC-AE (Alarms & Events): OPC AE servers are used to accept and exchange process alarms and events.
- OPC-DX (Data eXchange): It defines the way OPC server data is exchanged with other OPC servers.
- OPC-XML (XML Data Access): It defines schema and data representation formats based upon XML standard. This makes it possible to share & manipulate process control data across all operating systems – Windows, UNIX, Solaris, etc.
- Dynamic Data Exchange (DDE) is a communication protocol developed by Microsoft to allow applications in the Windows environment to send/receive data and instructions to/from each other. It implements a client-server relationship between two concurrently running applications.
- Wonderware SuiteLink uses a TCP/IP-based protocol. SuiteLink is designed specifically to meet industrial needs, such as data integrity, high-throughput, and easier diagnostics. This protocol standard is supported for Windows 2000, Windows 2003 Server, and Windows XP.
- SuiteLink is Not a Replacement for DDE. Wonderware recommends that DDE be used for internal client communication, and SuiteLink for communication over the network.
- DDE and SuiteLink identifies an element of data in an I/O data source program by using a three- part naming convention that includes the application name, topic name and item name. To obtain data from another application, the client program opens a communication channel to the server program by specifying these three items. Additionally, if the communication channel is between applications running in different computers, a node name must be specified too.
- Node: Name of the computer the I/O data source program or service is running on.(IP Number of respective System)
- Item: Name of the actual individual data point to be access once the communication channel is opened.
- Topic: It's an application-specific sub-group of data elements.
- Application: Name of the source program or service that provides I/O data to the client application. This is the name of the executable file without the extension.
- Today the acronym OPC stands for Open Platform Communications.
- OPC is the interoperability standard for the secure and reliable exchange of data in the industrial automation space and in other industries. It is platform independent and ensures the seamless flow of information among devices from multiple vendors.
- The OPC client software is a program that connects to the hardware, such as an HMI, SCADA, PLC etc. The OPC client communicates with the OPC server to receive data or send commands to the hardware
Following OPC specifications are used in industries:
- OPC-DA (Data Access): Provides access to real-time data. We can query most recent values of temperature, pressure, density, acceleration, and other types of process control data from OPC-DA server.
- OPC-HDA (Historical Data Access): This is used to retrieve historical process data for analysis. This data is typically stored in files, databases or remote telemetry systems.
- OPC-AE (Alarms & Events): OPC AE servers are used to accept and exchange process alarms and events.
- OPC-DX (Data eXchange): It defines the way OPC server data is exchanged with other OPC servers.
- OPC-XML (XML Data Access): It defines schema and data representation formats based upon XML standard. This makes it possible to share & manipulate process control data across all operating systems – Windows, UNIX, Solaris, etc.
Last modified: Friday, 10 April 2020, 3:38 PM