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Event executed when timestamp is updated

 
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Last Post by c.pinasanz 4 years ago
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 c.pinasanz
(@c-pinasanzarcinfo-com)
Posts: 42
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Hi,

I have a request from a customer. In the project there are several events configured with the expression ALL > ALL.
In fact, some variables in event, come from redundant PLCs. When there is a switch between PLCs, the timestamp is updated, but quality and value don't change. The event is executed anyway, because of the timestamp.
For this particular case, the customer does not want the event to be executed.
Any ideas on how to deal with this situation? Is there an expression for this case?

Thank you !!

Claudia

 
Posted : 14/10/2022 5:02 pm
LM
 LM
(@l-micaudarcinfo-com)
Posts: 383
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Hello Claudia,

There is an easy workaround I guess. In the Scada Basic function you check if the previous value and timestamp are different from the current value and timestamp.
The issue is that I think we don’t have this possibility in Scada Basic for now 🙁
It is probably possible with variable toolkit dll_

I suggest you create a SPR in order to have this directly in a Scada Basic event. Today we already have GETARG("TS_VALUE") and GETARG("VARVALUE_type").
It would be very good to have also GETARG("PREVIOUS_TS_VALUE") and GETARG("PREVIOUS_VARVALUE_type"), don’t you think?

@+

 
Posted : 14/10/2022 6:52 pm
 c.pinasanz
(@c-pinasanzarcinfo-com)
Posts: 42
Trusted Member
Topic starter
 

Hi Ludo,
I agree, what he is doing now is:
1. Save the previous value in another PcVue variable
2. Compare both variables in the scada basic program

I like your idea, I will create the SPR.

Thanks,
Claudia

 
Posted : 20/10/2022 8:27 pm
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