1.2.2. OPC ServersThe appearance of

1.2.2. OPC Servers
The appearance of PLC devices led to the specification of some large industrial projects
in the late 1980’s and early 1990’s, particularly in the automobile industry in which
Ford Motors was a prominent example. In order for vendors' products to interoperate,
several vendors got together to create a standard based on PLC communications. One
of these efforts was the industry task force that eventually became the OPC Foundation
(http://www.opcfoundation.org/). The OPC Foundation released the first set of
standards in 1994 based on Windows as the operating system and Ethernet networks as
the transport.
Introduction to GENESIS64 1-9
Introduction to
GENESIS64
OPC originally stood for Object Linking and Embedding for Process Control; a name
chosen because the technology was based on Microsoft’s inter-application
communication (IAC) standard at the time, OLE. The rise of the Internet led Microsoft
to update OLE with first, the Common Object Model (COM), and in rapid fashion
DCOM (Distributed COM). DCOM added the ability to communicate with remote
networked systems.
You can recognize software built using DCOM because it loads ActiveX components
into a browser or into a container application. GENESIS32 versions 5 through 9 all
used ActiveX technology inside container applications.
The OPC standard specifies a set of objects, interfaces (APIs), and methods that are
used by automation software in an open system. OPC bridges devices like PLCs and
DCS to client applications using applications called OPC servers that communicate
using the OPC protocol. An OPC server can be a local service running on the same
system as the client (also known as the localhost), on a server on the LAN, or
somewhere in the clouds (WAN).
OPC communication eliminates the need for developers to write individual device
drivers to connect clients to individual devices. As long as a client understands the
correct flavor of OPC, the connection or “subscription” may be made. OPC ended up
publishing a number of different specifications based on DCOM as they embraced
different classes of devices. Eventually OPC included:
 OPC Data Access (OPC DA). This set of standards connects real time data
acquisition devices to applications.
 OPC Alarm and Events (OPC AE). These standards provide event-based alarm
communication.
 OPC Historical Data Access (OPC HDA). Historical data access specifies how
to log data to a data store and retrieve the data for later analysis.
 OPC Security. This specification sets the protocol for applications to securely
communicate with OPC devices and systems.
 OPC Batch. The batch standard offers communication methods useful for batch
processing needs.
 OPC XML-DA. XML DA extended the Data Access specification so that it
communicates using XML over Microsoft Simple Object Access Protocol
(SOAP).
 OPC Complex Data. This specification extended OPC to include binary data,
complex data objects (like BLOBs), and XML documents.
Of the different standards it is only the first three – OPC DA, OPC AE and OPC AE –
that find widespread use.
1-10 GENESIS64 Standard Training Manual
You can now see the reasons for the origin of individual ICONICS GENESIS
applications to support each of the different standards:
 GraphWorX supports OPC DA access
 AlarmWorX is used for OPC AE access
 TrendWorX is used for OPC HDA access
Each application leverages the different capabilities of the individual types of OPC data.
The GenBroker service (introduced into GENESIS32 version 6) facilitates the need for
remote OPC communication, overcoming communication hardship via DCOM

Kết quả (Anh) 1:

1.2.2. OPC ServersThe appearance of PLC devices led to the specification of some large industrial projects in the late 1980 's and early 1990 's, particularly in the automobile industry in which Ford Motors was a prominent example. In order for vendors ' products to interoperate, several vendors got together to create a standard based on PLC communications. One of these efforts was the industry task force that eventually became the OPC Foundation (http://www.opcfoundation.org/). The OPC Foundation released the first set of standards in 1994 based on Windows as the operating system and Ethernet networks as the transport.Introduction to GENESIS64 1-9Introduction to GENESIS64OPC originally stood for Object Linking and Embedding for Process Control; a name chosen because the technology was based on Microsoft's inter-application communication (IAC) standard at the time, OLE. The rise of the Internet led Microsoft to update OLE with first, the Common Object Model (COM), and in rapid fashion DCOM (Distributed COM). DCOM added the ability to communicate with remote networked systems.You can recognize software built using DCOM because it loads ActiveX components into a browser or into a container application. GENESIS32 versions 5 through 9 all used ActiveX technology inside the container applications.The OPC standard specifies a set of objects, interfaces (APIs), and methods that are used by automation software in an open system. OPC bridges devices like PLCs and DCS to client applications using applications called OPC servers that communicate using the OPC protocol. An OPC server can be a local service running on the same system as the client (also known as the localhost), on a server on the LAN, or somewhere in the clouds (WAN).OPC communication eliminates the need for developers to write individual device drivers to connect clients to individual devices. As long as a client understands the correct flavor of OPC, the connection or “subscription” may be made. OPC ended up publishing a number of different specifications based on DCOM as they embraceddifferent classes of devices. Eventually OPC included: OPC Data Access (OPC DA). This set of standards connects real time data acquisition devices to applications. OPC Alarm and Events (OPC AE). These standards provide event-based alarm communication. OPC Historical Data Access (OPC HDA). Historical data access specifies how to log data to a data store and retrieve the data for later analysis. OPC Security. This specification sets the protocol for applications to securely communicate with OPC devices and systems. OPC Batch. The batch standard offers communication methods useful for batch processing needs. OPC XML-DA. XML DA extended the Data Access specification so that it communicates using XML over Microsoft Simple Object Access Protocol (SOAP). OPC Complex Data. This specification extended OPC to include binary data, complex data objects (like BLOBs), and XML documents.Of the different standards it is only the first three – OPC DA, OPC AE and OPC AE –that find widespread use. 1-10 GENESIS64 Standard Training ManualYou can now see the reasons for the origin of individual ICONICS GENESIS applications to support each of the different standards: GraphWorX supports OPC DA access AlarmWorX is used for OPC AE access TrendWorX is used for OPC HDA accessEach application leverages the different capabilities of the individual types of OPC data. The GenBroker service (introduced into GENESIS32 version 6) facilitates the need forremote OPC communication, overcoming communication hardship via DCOM