DDML 3.0 Documentation

Past DDML Versions (2.0)

Latest News

03-11-2008: KBSI proposed a number of changes to the DDML standard at the 117th RCC TG Meeting in Yuma, AZ. The slides from that presentation are here, and a document describing the proposed changes is here.

Click here to download the proposed schema (xsd) file.

Click here to browse the proposed schema in html format.

09-20-2007: DDML has been adopted by the Range Commander's Council as part of IRIG-106 Chapter 9, and has been published in the 106-07 standard. Documentation for past versions of DDML will remain on this page for historical purposes. However, for the latest DDML version documentation, check the RCC website: https://wsmrc2vger.wsmr.army.mil/rcc/index.htm.

03-09-2006: The complete DDML 3.0 schema is now available. If you have any comments or questions, please send them to JLHamilton@kbsi.com.

Changes in version 3.0 include:

	Attributes replaced by Elements
	<expr> element replaced with MathML <apply> element for derived variables
	Rules logic improved

03-09-2006: A preliminary version of DDML version 3.0 was presented at the 113th Range Commanders Council Telemetry Group meeting yesterday (3/8/2006). The slides presented at the meeting are available here.

08-25-2005: The slides presented at the 112th Range Commanders Council Telemetry Group yesterday are available here.

08-05-2005: KBSI will be giving a presentation on DDML 2.0 at the next Range Commanders Council (RCC) Telemetry Group meeting. The presentation will be given to the Data Multiplex Committee and will be held on the morning of Wednesday, August 24, 2005.

08-05-2005: Latest DDML 2.0 DTD and schema diagrams posted.

08-05-2005: "map" element added to DDML. This object serves as a container for other objects whose coordinates are specified in geographic latitude/longitude coordinates, such as RangeView's map annotations.

DDML Overview

The Data Display Markup Language (DDML) was developed by KBSI as part of the DDTF project to serve as the inter-lingua between data display languages supported by different vendors.

DDML has been designed with the following objectives in mind: (i) to include a standard terminology for describing data display components; (ii) to be robust and highly expressive in order to accommodate any data display language; and (iii) to be highly unified and not a loose grouping of XML-ized vendor formats.

DDML is built off of a layered structure (shown on the left of the figure below) that is parallel to a typical software layered architecture composed of graphics resources, visualization and user interfaces, information management, and persistence modules as shown on the right side of the figure. Parallel to those modules, DDML is also composed of four layers as described below:

	Graphics Resources: This layer is similar to "graphics resources" of a typical software tool. In DDML this layer includes the visual components of a data display system such as sliders, plots, and strip charts as well as low level graphic elements such as lines, rectangles, etc. Basic graphical shapes are modeled using a W3C recommended XML format called "Scalable Vector Graphics (SVG)".
	Dynamics: The dynamics layer handles the behavior of an object. It manages the rules and the variable instances attached to an object.
	Data Variables: Data variables are the links between the objects and the data sources. Data variables can be atomic or derived. Derived variables may use other derived or atomic variables in a mathematical expression.
	Data Sources: The last layer of the DDML architecture is the Data Sources layer. This layer handles various data sources such as text files, ODBC, network ports, and ports on DAQ cards.

At each layer, the parameters used to describe each DDML element are divided into two groups: DDML Attributes and Custom Parameters. DDML attributes are the most common and most necessary pieces of information needed to represent each element. They are stored in the element's attribute list. Custom parameters are used to store any vendor-specific information that is not a DDML attribute. These parameters are stored as DDML 'param' elements.