DDL - The HTML of the Field Technology
 

What DD's Really Do?
The HART Protocol operates in a host/slave environment where an instrument is queried and responds to a host. HART has a command structure that allows device manufacturers a great deal of latitude on designing a device. All HART devices must have a minimum command set in order to be compliant. These commands are called Universal commands. Devices may also have a number of optional commands called Common Practice Commands, Many devices implement manufacturer specific commands called Device Specific Commands. The DD allows access to all commands. DD aware host systems can then use the data and display it as the user desires.

DDL is a language to describe devices. A device description (DD) is stored as a text file. Similar to the presentation of HTML that is independent of an operating system and browser, a DD is displayed with a DD application.
A DD serves as a versatile information base and can be used to support the following tasks:
 
 
   
 
Engineering
  • Configuring of networks, gateways and Remote I/Os
  • Export / Import of device data
  • Upload / Download
  • Offline configuring
  • Comparison of parameter
  
 
Commissioning
  • Address setting
  • Visualization of process data
  • Simulation
  • Calibration, Adjustment
  • Online configuring
  • Identification of devices for a life list
Runtime
  • Displaying devcie and diagnostic states
  • Support of device exchange
  • Identification check
  
User Profiles
  • For the maintenance engineer reduced access to the device parameters
  • For the specialist full access to the device parameters
  • For device specific user profiles
  
Asset Management
  • Device state for maintenance, repair and fault removal
   
Online Help and Documentation
Overview for:
  • Variables, Dialogs, Methods
  • Value ranges, default values, units
  
 
Catalog and e-Commerce
  • Order Information
  • Process connection
  • Information about Manufacturer
 
HART® is a registered trademark of the HART Communication Foundation