Experimental Physics and
Industrial Control System

Hi all,

 

We noticed recently that if for instance the lower alarm limits are not explicitly defined in the EPICS database, CS-Studio reports all limits to be NaN. See here https://github.com/ControlSystemStudio/cs-studio/issues/2716 for a description and a following discussion.

 

Kay pointed out that even when the limits are explicitly defined as 0, the IOC reports them as NaN. Now this starts to smell like a bug. But before I submit a bug report, I wanted to ask if there is a reason behind this behavior? Maybe it is a feature and not a bug?

 

There is another interesting case, described by Kay in the above issue report, when only one HIGH and not HIHI is defined. How should this case be interpreted? The “Process Database Concepts” documentation ( https://docs.epics-controls.org/en/latest/guides/EPICS_Process_Database_Concepts.html#alarm-conditions-configured-in-the-database ) indicates that the alarm limits express a range, however not very explicitly. But this is not consistent with this case.

 

Any thoughts?