Versatile process variables management system

The central component of ProcessVars is a process variable management system, which administers variables in connection to a database and provides interfaces for access over a network.

Variables consist of names that can be addressed easily through grouping in point notation.


The data types of process variables are all basic types such as bit, int, double, string, datetime, blob as well as structures. Structures can be defined as datatypes or dynamically created through the schema of database tables or views. Single and multidimensional Arrays are supported as well.

The declaration of variables, actual data as well as the progression of data over time is saved to the database. The time course over the last n minutes, of the variables is stored in the RAM to ensure high performance access. The duration for which the data series are held in RAM or in the database can be configured.

Flexible Client/Server Architecture and efficient communication per Publish/Subscriber

ProcessVars is built in a Client/Server architecture and consists of a Windows service for administration of the variables and a .Net assembly for access of the variables in a network.

For the communication between client and server the protocol TCP/IP and JSON are used.

The communication follows the Publish/Subscriber model:

The client subscribes one or more groups of variables to a server service. After a successful subscription the client is provided a snapshot of the current variable values. The server service subsequently publishes the client any changes of subscribed variables.

The communication connection between client and server will automatically reconnect in case of any interruption (network error, …), thus allowing deployment in WLAN and VPN environments.

Virtually unlimited application possibilities through scripting

The core functionality of ProcessVars can be expanded almost unlimited via the scripts classes . Script classes can be developed in C # using the .NET Framework

They are stored in a script file. Newly added or modified script classes are loaded automatically by the service, translated and if error-free carried out.

The scripts can be efficiently developed and tested for example with Microsoft Visual Studio Express Edition (at no license cost).

Methods of script classes are executed:

  • For validation of variable changes
  • Cyclic
  • By change of variables or a group of variables
  • Over a client interface

The access of process variables in c# script classes occurs directly by name. This means there is no need of calling methods to read the variables. Writing to variables can occur consistently over a commit block. In addition to access of process variables the Server service allows running scripts methods classes via the client assembly.

Configurable communication via OPC

OPC is the manufacturer -independent standard for communication in automation technology.

OPC servers are available for all current automation systems which offer a standardized software interface over Microsoft DOM (DCOM). ProcessVars communicates via these interfaces with automation systems. Through easy configuration process variables can be connected with data points of the automation systems. The ProcessVars OPC Bridge is a Service that synchronizes the linkage of data points; through which both reading as well as writing access to data areas of automation systems is possible.

The characteristics of ProcessVars OPC communication are:

  • Storage of the OPC definitions for the server, groups and items in the database system
  • Cyclic or event based communication
  • Multiple OPC servers are configurable

For the communication with SIMATIC S5/S7 there are further protocols available:

  • S7 Write / Fetch Protocol
  • S5 P3964 / RK512 Protocol

There are script classes available for the communication with diverse Systems, such as scales, assembling tools, temperature measurement equipment, analyses equipment and much more. In addition to access of process variables the Server service allows running scripts methods classes via the client assembly.

Easy generation of interactive user interfaces with WPF

ProcessVars provides a framework for the development of user interfaces with access to process variables and functions via WPF (Windows Presentation Foundation). The properties of WPF elements can be bound directly in XAML to process variables.

WPF simplifies the advantages of DirectX, Windows Forms, Adobe Flash, HTML and CSS. Application interfaces are described declaratively via the XML based Extensible Application Markup Language (XAML).

There are several XAML Editors available with which interactive, professional user interfaces can be constructed. An exceptional product is Microsoft Expression Blend which is included in the free Visual Studio Express Edition.

For a reduction of expenses in the distribution of user interfaces created with ProcessVars custom groups of XAML controls are provided. These are stored with a specific name in a directory on the server. The XAML elements can are imported from the ProcessVars Server when any change occurs, translated and when correctly translated distributed as process variables to the clients. The user interface of the clients is dynamically updated through this process.

Animated Process Graphics with ProcessVars

In automation technology the states of the machines, their actuators and sensors are visualized through graphics. ProcessViews is a Graphic Editor which offers comfortable construction of animated process graphics in a simple manner. For the animation of the objects the process variables can directly be bound to the objects in the editor. The graphic editor exports a XAML file with bound process variables which can be integrated in the user interface.