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
    - base64Decode()
      Decodes base64 encoded data.
    - base64Encode()
      Encodes data in the base64 encoding.
    - baseName()
      The function returns the last part of a file path.
    - beep()
      Issues a beep.
    - bitmapEditor() - obsolete
      This function opens the bitmap editor. To be able to use the function, the PVSSBitmapEditor.dll has to exist in the directory <version_path>/bin (obsolete from version 3.5 up).
    - blobAppendValue()
      Works like blobSetValue(), but the value is appended to the blob.
    - blobGetValue()
      Reads "value" from byte offset "offset" with "len" bytes from blob.
    - bloblen()
      The function returns the length of a blob in bytes.
    - blobRead()
      The function blobRead() reads the content of a file into a blob variable.
    - blobSetValue()
      Writes "value" from byte position "offset" with "len" bytes to the blob.
    - blobWrite()
      The function blobWrite writes the content of a blob variable into a file.
    - blobZero()
      Sets blob length to len bytes and initialize the blob with "0".
    - byteSizeToString()
      Converts a filesize in bytes to a string (for example, with getFileSize()).
  - Funtions C
  - Funtions D
  - Functions E
  - Functions F
  - Functions G
  - Functions H
  - Functions I
  - 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.

blobZero()

Sets blob length to len bytes and initialize the blob with "0".

Synopsis

int blobZero(blob &target, int len);

Parameters


Parameter	Description
&target	The Blob
len	Length of the blob

Return Value

With an error -1, otherwise the length of the blob.

Errors

Missing or wrong arguments

Descriptions

If data are sent in a blob, then the data have to be treated with CTRL functions for using the data in CTRL. The function blobZero() sets the blob length to len an initialize the blob with "0".

Example

main()
{
  blob target;
  int len;
  string s;
  s = "FFAB003A";
  target = s;
  DebugN(target);
  len = 30;
  DebugN("Blob Zero : " + blobZero(target, len ));
}

Assignment

Blob functions

Availability

CTRL