Siemens ST PCS 7 manual OpenPCS, OPC DA data access server, OPC HDA historical data access server

© Siemens AG 2007

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OpenPCS 7

■Overview ■Function

OS clients OPC clients

OpenPCS 7	Microsoft
	Visual Basic
server
	for Applications
(OS multi-client
	Microsoft Excel
with OpenPCS 7)
	SAP

OS server

Automation systems

Systems for production planning, process data evaluation and management (OPC clients) that are at a higher level than the process control system can access SIMATIC PCS 7 V7.0 pro- cess data by means of the OpenPCS 7 server. The OpenPCS 7 server collects data for the OPC clients. Depending on the sys- tem configuration, these data may be distributed across different SIMATIC PCS 7 stations (OS server, central archive server). The OpenPCS 7 server covers the distribution of data with re- gard to the period (OS1 / OS2 /… / CAS), the location (OS1 / OS2 / … ) and the redundancy (OS1 master / OS1 standby …).

OpenPCS 7 replaces the @PCS 7 previously available in the SIMATIC PCS 7 context, and is simultaneously the pendant to the Connectivity Pack of the WinCC SCADA system. Access to the data of SIMATIC BATCH is therefore impossible.

■Design

The OpenPCS 7 server can be operated in two different config- urations:

•As autonomous OpenPCS 7 server based on a SIMATIC PCS 7 Industrial Workstation in the client version (recom- mended preferred configuration), or

•as multi-functional SIMATIC PCS 7 Industrial Workstation, cli- ent version, with OpenPCS 7 server and OS client functional- ities (OpenPCS 7 server/OS client).

Each OPC client without PCS 7 OS/WinCC license requires a WinCC/Client Access license for access to the OpenPCS 7 server. The client access license referred to an OpenPCS 7 server is available in two versions:

•As access privilege for an OPC client and

•as access privilege for any number of OPC clients.

The OpenPCS 7 interface is based on the OPC specifications (Openness, Productivity, Collaboration) that mainly make use of Microsoft’s DCOM technology (Distributed Component Object Model) for communication between the applications. It supports the following standardized access options:

OPC DA (data access server)

For read and write access to process values according to OPC specification OPC DA V1.00, V2.05a, V3.00

As an OPC DA server, the OpenPCS 7 server provides other ap-

plications with current data from the OS data management. The 5 OPC client can log itself on to ongoing changes or also write val-

ues.

OPC HDA (historical data access server)

For read-only access to archived process values according to OPC Specification OPC HDA V1.20

As an OPC HDA server, the OpenPCS 7 server provides other applications with historical data from the OS archive system. The OPC client, e.g. a reporting tool, can specifically request the re- quired data by defining the start and end of a time interval. Nu- merous functions, e.g. variance, mean value or integral, already permit preprocessing by the HDA server and thus contribute to- wards reduction of the communications load.

OPC A&E (alarm & events server)

For read-only access to messages, alarms and events accord- ing to OPC Specification OPC A&E V1.10

As an OPC A&E server, the OpenPCS 7 server passes on OS messages together with all accompanying process values to the subscribers at the production and corporate management lev- els. They can of course also be acknowledged there. Filter mechanisms and subscriptions ensure that only selected, mod- ified data are transmitted.

OPC "H" A&E (historical alarm & events server)

For read-only access to archived alarms and messages

By means of a Siemens extension to the OPC standard interface, the OpenPCS 7 server is also able to transmit historical alarms and messages from the archive to the subscribers at the produc- tion and corporate management levels.

OLE-DB

Simple, standardized direct access to the archive data in the Microsoft SQL server database of the operator system is possi- ble with the OLE-DB. Through this, all OS archive data are ac- cessible with the accompanying process values, message texts and user texts.

Siemens ST PCS 7 · November 2007

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