AdvaBuild DisplayBuilder Elements
I have a general question about the paramter settings of the master (unix) advabuild display elements. Especially abut the update settings of different element types(analog/digital/motcon/valve,...).
What´s the behaviour of the settings "demand" and "demand+event" when using analog and digital signals?
Our default setting at the moment is "demand+event+update x sec." when using digital signals.
I it right that changing the settings to "demand+event" has the same effect for displaying this element?
Reason for this question is, that we have to minimize CPU-load and therefore we have to decrease update-rate from display elements to save load.
Another question is how to build new elements, has anybody some dokumentation about it?
Demand means a single shot update as a display containing the object is brought up the first time. You should always use Demand to ensure quick call-up performance.
Event means update anytime there is a significant binary Event for the object in question. Example of Events; object selected/deselected, object blocked/deblocked, alarm blocked/deblocked, object entering alarm state, object leaving alarm state, digital signal changing state etc. You need Event to get quick visual feedback on operator comands.
Cyclic update is selfexplanatory, dynamic data will be updated every 1/3/9 seconds. Remember that this is a hard cycle executing in the controller, it does not for example start when you open a display.
For analog signals you should not use Demant+Event, since you would never see the analog value update other than at the events described above. For digital signals you could in theory used Demand+Event since the signal state change is considered an event, however, if for whatever reason, one single event update signal is lost, the graphic will continue to show the wrong state.
My recommendation; analog style objects; Demand+Event+3 sec, digital style objects; Demand+Event+9 sec.
Building new display elements for Unix AdvantStation is not for the faint of heart. There were some training classes way back, and the training material from those classes may be your best bet.
> "Reason for this question is, that we have to minimize CPU-load and therefore we have to decrease update-rate from display elements to save load."
This is not a suitable way to reduce total CPU load. There are some things you should check first .....
- What is the current total CPU load ? For an AC450, anything less than 90% is not a problem. Even over 90% is quite OK, it's just annoying wating for the On-Line builder so much.
- How much of your total CPU load is comming from TTD logging ? You can kill the TTD logging tasks and compare CPU loads. (DCTA200, 500 and 600 if I remember correctly )
- Have you run an ANPER and compared the loads for each system task ?
- Have you made ABSOLUTELY sure that there are no unresolved display elements on any Advant graphics anywhere in the system. The symbol resulution task on the AC450 will continually try to resolve bad element references and this can make the controller load seem quite high.
- High loads from Advant Subscription tasks are usually because you are trying to subscribe data too quickly. Reading data at 1sec updates from an AC450 is not sensible except for very small amounts.
I might still have some notes somewhere on Building advant display elements, but they are hand written and not very good. I remember the process as being HORRIBLE.