Hello everyone,
Whenever I open some control modules online, they appear to be in read-only state, and I cannot do any online changes.
This is only happening with some of the control modules, is this some sort of security feature that you can assign on selective control modules?
In reply to andrewduffy:
Thanks andreduffy, I haven't worked on class-based modules in DeltaV and this solved my problem, as it was a class-based module. Did the modifications in the parent class.
In reply to Maarten van der Waal:
I think Maarten is trying to bring some much needed clarity to this discussion.
Online = Information is in the Controller
Offline = Information is in the database.
Class-based modules will only allow database (offline) configuration for parameters which have been configured to 'allow instance to be configured'.
When using control studio online, (as depicted in the original attached picture), configuration parameters (even those NOT configured with 'allow instance to be configured') CAN still be changed online provided:
1. The DeltaV user has access
2. The workstation has access or the 'restrict online changes to areas assigned....' option is not checked.
3. The parameter is of the variety that can be written to. For instance, you can't ever write to MSTATUS for a module or the PV of an AI block as these are calculated internally by the controller logic at run time. Other parameters, like an AI block L_TYPE, can only be written to online when the AI is in OOS mode.
If you indeed had a problem wiriting to a parameter on-line it may have been due to one of these conditions. The Read-only indicator in the title bar refers to the database state of the module, not the ability to change parameters (i.e. control) on-line.
Changing the class may have fixed your original issue for that particular module instance, but how does it affect all other instances?
In reply to Youssef.El-Bahtimy:
Hello Youssef,
Thanks for your elaborate explanation!
When we change the parent class, all the instance control modules which inherit the properties of the parent module, gets updated; so in my case, when I updated the parent class, all my instances were updated automatically.