Siemens SIMATIC OpenPCS 7, Руководство по эксплуатации функций

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● Connection via PROFIBUS
● Connection using input modules or output modules
OPC DA client
Data access clients can, for example, be Excel tables in conjunction with Visual Basic for
Applications (VBA). They may also be extensive applications created with Visual Basic or
Visual C++.
OPC DA server
Basically an OPC DA server makes process data available to an OPC DA client for read and
write access.
OPC DA servers can be programs that, for example, allow access to an automation system
via a serial interface. More complex programs are possible that provide access to large
numbers of tags on numerous devices using extensive communications mechanisms. This is
the case with OpenPCS 7.
Access options using OPC DA
OPC Data Access is a specification for access to process data using process variables. An
OPC DA server manages the process variables and the various options for access to these
variables. The following types of access are possible:
● Reading the value of one or more process variables (tags)
● Modifying the value of one or more process variables (tags) by writing a new value
● Monitoring the value of one more process variables (tags)
● Reporting value changes
6.3.3 How the OPC DA server works
Requirement
To be able to set up successful OPC communication, the following requirements must be met:
● The PCS 7 OS project and the OPC DA server must be loaded and started.
● The computer of the OPC DA server can be reached by the OPC DA client via its IP address.
Note
In your PCS 7 OS project, variables can be grouped together in variable groups to provide
structuring. The variables must not have the same name as a variable group.
OpenPCS 7 interface
6.3 OPC Data Access (OPC DA)
OpenPCS 7
Function Manual, 05/2012, A5E02780178-02
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