Presentation Independence of Data Introduction
The ECDIS display is the window through which the database (ENC) can be viewed.
The Independence of data is the concept that when an object is not displayed on the screen it is still there and is able to trigger alarms.
![WINWORD_2016-09-13_09-50-21](https://www.emaritimetraining.com/wp-content/uploads/2016/09/WINWORD_2016-09-13_09-50-21.jpg)
By interrogating the chart, information about an ENC can be viewed. The following information is provided:
- Chart Legend
- Chart Type
- Name
- Agency Code
- PL Version
- Edition and Update Number
- Format Number
- Issue Date
- Navigation Purpose
- Compilation Scale
- Horizontal Datum
- Vertical Datum
- Sounding Datum
- Projection
- Depth Units
- Height Units
- Object Information
- Update History
- Text and Diagrams (from File)