Version Information
Release Notes, Update information, Certifications and Frequently Asked Questions.
Concepts
Your first step into modern and powerful process visualization.
Deployment
Topics, you need to know, before using WinCC OA.
Security
Go beyond the norm in cybersecurity.
Engineering
Powerful tools for easy or complex engineering tasks.
Data Management
Classify, structure and archive your data.
Business Logic / Control
Endless possibilities in data processing for your projects.
- Introduction to CTRL
  An introduction to the product's own programming language Control(CTRL).
- Control Classes
  The overview of classes available in Control.
- Types of Control Functions
  An overview of the types of functions distinguished within Control.
- Control graphics
- CONTROL Functions
  - Funtions A
  - Funtions B
  - Funtions C
  - Funtions D
  - Functions E
  - Functions F
  - Functions G
  - Functions H
  - Functions I
    - iec61850_createRcbDp()
      This function allows to create internal RCB data points.
    - iec61850_deleteRcbDp()
      Deletes the given internal RCB data point.
    - imageToFile()
      Stores an images which was created using getPanelPreview() (or using QVarPicture) to a file on the disk.
    - initializeAesPermissionCustomization()
    - initializeAesRowCustomization()
    - inputRecorderGetScript()
      The function returns the script after the recording is stopped.
    - inputRecorderIsRecording()
      The function shows if the input recorder is currently recording.
    - inputRecorderStart()
      The function starts the input recording.
    - inputRecorderStop()
      The function stops the input recording.
    - invokeMethod()
      Invokes a method of a EWO widget or of a reference created via CTRL++/OOP.
    - isAckable()
      The CTRLLib.ctl function is called before an acknowledgment with a simple configuration (see Acknowledge).
    - isAlertAttribute()
      Indicates whether the passed attribute is an alarm attribute. That means whether is can be queried with alertGetPeriod(), alertConnect(), SELECT ALERT or can be set with alertSet().
    - isAnswer()
      The function isAnswer() checks whether the workFunction() of a dpConnect() is called the first time after the connection was established via dpConnect().
    - isAudioAvailable()
      The function checks if audio is available for the playback.
    - isConnActive()
      The function checks whether the connection to the event manager is active. The function is used in split mode to determine the active EM connection. The host the user interface is logical connected to is shown in the system overview. See chapter System overview with redundancy.
    - isConnOpen()
      The function checks if the connection from the own user interface manager to the event manager exists. The function is used in a redundant system. With this function, you can find out to which event manager the UI is connected to (to the left or to the right).
    - isDbgFlag()
      Queries if a flag with the defined name or number has been set.
    - isDialog()
      Checks if a panel was opened with openDialog().
    - isdir()
      The function checks if a specified directory exists.
    - isDirectory()
      The function checks if the specified string is a directory or a file. The function returns 1 if the specified string is a directory and 0 if the specified string is a file.
    - isDistributed()
      The function returns TRUE if the entry distributed = 1 exists for the manager in the config file. If the entry distributed in the config file is not 1, FALSE will be returned. In case of a remote UI, the distributed entry is set by the Data Manager when distributed = 0/1 does not exist in the file. In this way, also other systems than the own local system can be accessed.
    - isDollarDefined()
      This function queries whether a specific dollar parameter exists.
    - isDpTypeStruct()
      Checks if a data point type is a struct type.
    - isDpTypeSumAlert()
      Checks if a sum alert or a normal alert can be configured for a data point type.
    - isEvConnOpen()
      Returns the status of the connection to the Event Manager.
    - isfile()
      The function tests if a specified file exists.
    - isFunctionDefined()
      Returns whether a specific function exists or not.
    - isInBrowser()
      Verifies whether the UI Manager is running in the Web Client plugin inside the web browser.
    - isinf()
      Indicates whether the returned value of a mathematical function is an infinite value.
    - isInstanceOf()
      This function determines if the given instance of a class is an instance of a specific class. Additionally it can be used to check if an enum is of a specific enum-type.
    - isMobileDevice()
      This function queries if the device from which the function is called is a mobile device or not.
    - isModeExtended()
      This function returns whether the Vision has been opened in extended mode (configuration mode) or not.
    - isModuleOpen()
      Specifies whether a particular module is open.
    - isMotif() - obsolete
      Specifies whether the user interface is UI Motif (obsolete as of version 3.5. The return value is always FALSE ).
    - isnan()
      Indicates whether the returned value of a mathematical function is a NaN (Not a Number).
    - isPanelInGedi()
      The function returns TRUE when the panel where the function is used is open in GEDI.
    - isPanelOpen()
      The function returns whether a particular panel is open.
    - isPaused()
      The function checks if the playback is paused.
    - isPlaying()
      The function checks whether the playback is playing.
    - isProgressBarOpen()
      The function checks, whether a progress bar is open.
    - isReduActive()
      Returns TRUE if the event manager to which a CTRL or UI manager is connected is currently active.
    - isReduDp()
      The function isReduDp() checks if the specified data point is redundant.
    - isRedundant()
      This function returns whether the project has been configured as redundant.
    - isRefresh()
      With the function isRefresh(), you can check whether the workFunction of a dpConnect() has been triggered by a redundancy switch or has been triggered when trying to establish a connection to a distributed system.
    - isRemoteSystemRedundant()
      This function returns whether the project has been configured as redundant.
    - isSeekable()
      The function checks whether a playback can be searched for.
    - isSplitModeActive()
      Returns whether split mode has been activated in the system.
    - isStopped()
      The function checks if the playback is stopped.
    - isTableAckable()
      This libCTRL.ctl function is called before an acknowledgment of a table, when this has been realized with simple configuration. The function helps to customize a project.
    - isVideoAvailable()
      The function checks if video is available for the playback.
  - Functions J
  - Functions K
  - Functions L
  - Functions M
  - Functions N
  - Functions O
  - Functions P
  - Functions Q
  - Functions R
  - Functions S
  - Functions T
  - Functions U
  - Functions V
  - Functions W
  - Functions X
  - Functions Y
  - Functions Z
- CtrlExtension
  The CtrlExtension allows the addition of custom C++ code.
- CTRL Debugger
  You can use the CTRL debugger to debug the Control programming language. The debugger can be used via its own panel, which also enables the monitoring and setting of variable values during the execution of a script.
- SQL in CONTROL
  The database functions enable you to quickly carry out value queries on data points and elements.
- API Manager
  The WinCC OA API (Application Programming Interface) offers a number of functions adding special Managers to this process control system.
Data Visualization
User interfaces, Trends and Reports for every purpose and device.
Southbound Interfaces
The process connection to the actual machines/sensors.
Northbound Interfaces
Your portal to the cloud or supervising systems.
Web Connectivity / Network Interfaces
Data exchange, APIs and web technologies
User Management
All about authorization, authentication and login-customization.
Availability
How to get your system uptime to the maximum.
Reporting
Create state of the art project reports without limits.
Addons
Useful tools and enhancements for special demands.
Reference Tables
Detailed and extensive content for special project adaptation.
Videos & Tutorials
Explore the capabilities of WinCC OA with our carefully selected collection of video tutorials and guides.
WinCC OA Documentation
Basic information about terms and functions within the documentation.
Disclaimer
A brief clarification of liability exclusions or legal notices.

isEvConnOpen()

Returns the status of the connection to the Event Manager.

Synopsis

bool isEvConnOpen();

Parameters


Parameter	Description
none	-

Return value

"true" in case of an existing connection, otherwise "false".

Error

Description

The function isEvConnOpen() is used to query whether the manager in question (Control, UI) is connected to the Event Manager or not.

Example


main()
{
  DebugN(isEvConnOpen());
}

Assignment

Miscellaneous functions

Availability

CTRL