FF Quality and Status information

[jlg320]

Sorry for such a simple question; I'm a new engineer. Where is a good source of information explaining the Quality, sub-status, and Limits information in the FF Status byte? i.e. what and where is the FF standard defined?

For example, the "Substituted value from Device" substatus of Uncertain: When would this manifest itself?

Thank you very much for any help.

JLG
Tri-Cities, Washington

[Robin Burnikell]

Hi JLG,

I do not know where you can get hold of FF specs for free that would give you the information you are after (I believe you have to become a member of the FF - which costs - to get hold of the specs).

The example you quote is the "substituted" value of "Sub-status" of a "status" with "Quality" of "Uncertain". This can arise only when a function block is in "Manual" mode. It informs subscribers to the "Output" that it is "disconnected" from the "Input" of the same block.

I know I am biased (I work for Smar) but I would recommend looking at the Smar Function Block Manual. It is the best I have seen from anyone especially as Smar has implemented more Fieldbus function blocks than any other supplier so it almost covers them all in a lot of detail with example configurations etc. However it is 300 pages! In it though is a section that describes the status value and what influences it.

You can access it from the smar web site www.smar.com (http://www.smar.com/) click on "by Model", select "A to E", select "DFI302", login in the left hand pane (you will have to register if you are not already registered), click on "Manuals", select "Foundation Fieldbus Function Blocks manual" to start the download.

For all engineers in Smar this book is our FF system configuration bible!

Regards,

Robin

[Heather Santos]

FYI,

You do not need to be a member of the Foundation to purchase specifications. Members are, however, given discounts on specs, tools, etc.

Check out our catalog for more information: http://www.fieldbus.org/index.php?option=com_content&task=view&id=144&Itemid=319