At a Glance

A Device DDT is a DDT predefined by the manufacturer and not modifiable by user. It contains the I/O language elements of an I/O Module.

Illustration:

Device DDT structures like DDT structures can contain:

• EDT

• DDT

• Array of EDT and DDT

The DDT types are structures whose size (the number of elements of which they are composed) depends on the channel or the input\output module that they represent.

In the current implementation, an I/O Module supports only one Device DDT type.

The difference with a conventional structure is that:

• the DDT structure is predefined by the manufacturer

  • the DDT structure supports EBOOL

  • the DDT structure supports type with extracted bits