OLE Automation Server
5.1
Introduction
Introduction
Subject of this sub-section
What's in this
Section?
This sub-section makes some general points concerning the OLE Automation server
This Section contains the following Maps:
Topic
Introduction to the OLE Automation server
OLE Automation server operating modes
Page
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OLE Automation Server
Introduction to the OLE Automation server
Introduction The OLE Automation Server PL7 functionality offers the possibility of executing the
PL7 in a programmed, non-interactive mode (i.e. without operator intervention) for applications external to the PL7. You use PL7 OLE Automation Server client application terminology.
PLC
Server
Client
Applications clients
PL7
*.stx
Conforming fully with the standard defined by Microsoft in its OLE package to respond to this need, PL7 now features a standard, public interface, which is independent of the client application programming language.
l l l l
The characteristic principles are: automation of repetitive tasks delegation to PL7 of processing tasks that only it can handle access to application information contained in the *.stx files more generally, development of higher level integrator type function, with encapsulation of PL7 specific implementation details.
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OLE Automation Server
Context of use The OLE Automation server PL7 functionality is built into PL7 Pro. It is installed and used under the same installation and use conditions as PL7. The OLE Automation server is supported by the Microsoft OLE Automation run-time provided with
Windows 95, 98 and NT
Note: To create an OLE server client application, you must know one of the l l l following OLE Automation programming languages:
Microsoft Visual Basic, version 5.0 or above
Microsoft Visual C++, version 4.2 or above
Microsoft VBA in Excel, version 5.0 or above.
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OLE Automation server operating modes
General
Description
In addition to the PL7 operating mode known up until the present which is designated as "interactive", where the PL7 reacts to operator inputs only, there is now the OLE automation server operating mode where the PL7 can also react to commands transmitted from an OLE client application.
Operating mode selection is dependen on the PL7 start procedure: l Interactive mode is initialized during PL7 start via Windows (Start menu/
Programs/ Modicon Telemecanique/PL7 Pro.).
l Server mode is selected if the OLE Automation PL7 server is invoked in the programming of an OLE client application. An instance can not change the current mode.
Each time a client application invokes the OLE Automation PL7 server, a specific
PL7 instance is started, independently of any other instances which may be in progress. Any number of PL7 instances in server mode or interactive mode can be running on the same terminal. The instances are all completely independent of each other and so can each run in their own context.
For all of these instances the same denial rules concerning concurrent access to an
STX application or a PLC apply, these being: an STX application or a PLC can only be handled by one instance at a time.
This rule was developed for the OLE Automation PL7 server which can open an already open STX application but not save it. In the same way, it can perform a PLC
—> PC transfer, on explicit demand, from a reserved PLC.
A client application can instantiate several competing "OLE Automation PL7 servers".
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