WinCC.net
Home
FAQs
Downloads
Feedback

FAQs

Explaining the Connectivity Pack Option

1. INTRODUCTION

It is a relatively simple task to set up a WinCC system to collect data, alarms and events from the process. This information is then seamlessly stored in a set of SQL Server databases.

This data can be easily viewed using the tools provided with WinCC. Process data can be viewed in trend or tabular format. Users can dynamically change the points being viewed and the time ranges. For alarm and event data, the inbuilt Alarm Control Window allows users to easily filter the information displayed. Finally the Report System allows for the creation of dynamic reports based on the data stored in WinCC.

However there is a growing need with customers to take data analysis further. It is not always sufficient to filter an alarm display to show all occurrences of a particular fault – instead, what is needed is a breakdown of total occurrences and durations of different types of alarms for each machine for a given shift. Process data needs to be exported to a spreadsheet package, such as Microsoft Excel, for further processing. Data stored in WinCC needs to be merged into other database applications, such as Oracle or SAP.

WinCC offers several options that accommodate this need for external analysis of data. These options are:

  • Dat@Monitor

  • IndustrialDataBridge

  • Connectivity Pack

This document will describe when the Connectivity Pack (CP) is needed and briefly detail how it should be used.

It should be noted that both Dat@Monitor and IndustrialDataBridge are applications that provide a graphical user interface (gui). This makes them relatively easy to configure as the majority of the configuration is done through wizards. The Connectivity Pack is a collection of drivers that must be programmed

2. WHAT IS IT

The Connectivity Pack (CP) is a collection of drivers that allow a programmer to access the WinCC runtime data stores. It comprises of the following drivers:
  • OLEDB
    An OLEDB provider that allows access to the WinCC runtime data stores for database programmers

  • OPC-XML (Direct Access)
    This driver is also installed with WinCC and allows access to real-time tag values

  • OPC HDA (Historical Data Access)
    This driver allows access to the WinCC runtime process data stores using the OPC HDA standard interface

  • OPC A&E (Alarms & Events)
    This driver can be used for accessing and acknowledging alarms and events

3. WHY USE IT

As mentioned above, there are options that allow data to be extracted from WinCC into external applications such as Excel, a CSV file or a web page. These applications have controlled access to the WinCC data stores and are therefore limited in the way they present the data.

Dat@Monitor allows for simple data extraction and reporting on a scheduled or ad-hoc basis. IndustrialDataBridge allows real-time data to be exchanged between two sources, e.g. writing WinCC tag values to an Oracle database in real-time.

However if there is a need to build more complex reports or to exchange aggregated data from WinCC to another source, this is when the CP is useful. There is no application provided with the CP so how the data is extracted, when and to where is completely customisable.

Additionally, access to the WinCC runtime data stores is only supported when using a driver from the CP. Access via native MS SQL Server tools is not supported and can lead to unforeseen problems.

4. WHERE IS IT?

When you install the CP you do not get an executable program that you can start up. What you get are several drivers that can be used to access the WinCC data. This is because the CP is a developers’ tool and not a users’ application.

The drivers are used programmatically in packages such as Excel, Visual Basic, Active Server Pages or Data Transformation Services.

5. THE WINCC OLEDB PROVIDER

A commonly asked question is regarding the purpose of the WinCC OLEDB Provider when there is a native OLEDB Provider built into MS SQL Server. To understand the answer, once must appreciate the purpose of OLEDB Providers.

An OLEDB provider allows you to access data stored in a software system (e.g. a SCADA package) as though it was stored in an SQL compliant database. It is usually developed by the software manufacturer and allows access to encrypted or non-SQL compliant data. It allows the data to be accessed using MS SQL Server tools such as Linked Servers or Data Transformation Services (DTS)

Although WinCC stores its runtime data in MS SQL Server databases, it is not advisable to access the data using the MS SQL Server OLEDB Provider for the following reasons:

  1. It is not supported!

  2. WinCC runtime data is not stored in one database but instead will span across a multitude of databases depending on the system configuration. The WinCC OLEDB Provider offers transparent access to the data and hides the complexity of how the data is stored

  3. The logged process data, collected from the Tag Logging System, is usually compressed when data is logged at a fast rate which makes it unreadable using standard SQL. The WinCC OLEDB Provider seamlessly decompresses the data into a readable format

6. GETTING THE MOST OUT OF THE CONNECTIVITY PACK

In order to use the CP successfully, a level of knowledge of certain programming technologies and development tools is required.

SQL (Structured Query Language) An ANSI standard computer language for accessing and manipulating databases

A good grounding in SQL is highly recommended in order to understand the data access capabilities offered with the WinCC OLEDB provider

A good reference site is http://www.w3schools.com/sql/default.asp
Microsoft SQL Server This is the database engine that WinCC uses to store its runtime data
ADO (ActiveX Data Objects) A programming interface to access data in a database. It can be used in programming languages such as Visual Basic, VBA, VBS or C++

ADO is commonly used with the WinCC OLEDB Provider to retrieve WinCC data into a client application such as Excel or VB

A good reference site is http://www.w3schools.com/ado/default.asp
DTS (Data Transformation Services) A set of tools to import, export, and transform heterogeneous data between one or more data sources

DTS offers a simple way to extract data in the WinCC data stores into standard MS SQL Server database tables

A good reference site is http://www.microsoft.com/sql/evaluation/features/datatran.asp

2007 Salma Ghafoor