EDDL Requirement

[mithunbiswas]

Why do we need to specify EDDL in FF spec. If we are specifying DD/CFF is it not enough. For what reasons/applications do we need to specify EDDL. Can user please help in understanding the requirements of EDDL, the difference between the DD/CFF and the EDDL.

[boblatt]

All registered FF devices must have a tested DD in order to be registered at the Fieldbus Foundation so specifying registered FF devices is all you need to ensure there will be a DD available. What is optional in the DD is the definition of the user interface screens used to configure and diagnose issues with the device. Without these user interface screen definitions in the DD the host system will simply display lists of parameters based on the blocks they are contained within in the device rather than easier to use task oriented screens provided by the device manufacturer. Specifying the device manufacturer provide these user interface screens might be something to consider in the specification.

Now here are some DD terms and acronyms that may provide some clarity in terminology.

DDL - Device Description Language - the language used to write Device Descriptions
DD - Device Description - the machine readable file provided by the device manufacturer
EDDL - Electric Device Description Language - same thing as DDL. The 'E' for Electronic came along when the language was standardized by the IEC.
EDD - same as DD
CFF - Common File Format - the .ini type file used to provide the machine readable device Capability File used by the host system for off-line discovery of device details that can not be included in the DD

[jberge]

If you want to see what some of these setup and diagnostics screens look like, check out this microsite on intelligent device management:
http://www.eddl.org/DeviceManagement/Pages/default.aspx
Click on "Device Diagnostics" and "Setup/Configuration"

Cheers,
Jonas