Hi Guys...

Another newby in Osisoft PI System here, I have some questions on PE tag.

I have a PE tag ('PE_Tag') with 'Event-Based scheduling'.
It will be trigged whenever tag ('Trigger_Tag') is triggered.
'Trigger_Tag' is a digital tag which has the CLOSE/OPEN value

The equation of the PE tag is :

IF TagVal('Trigger_Tag') = "CLOSE" THEN IF TagVal('Trigger_Tag') = PrevVal('Trigger_Tag') THEN TagVal('PE_Tag', '*') ELSE TagVal('PE_Tag', '*') + 1 ELSE TagVal('PE_Tag', '*')

I have 2 problems:

1. I noticed that whenever there is an event for 'Trigger_Tag', the 'PE_Tag' will be executed twice. The timestamp of each execution of the 'PE_Tag' is 1 second difference.
Do you guys know what this happen?

2. My 'Trigger_Tag' was set to have max time for exception test = 60 minutes, and max time for compression test = 60 minutes.
I notice that whenever my value pass the exception test, the latest value of the tag in PI SMT > Archive Editor will be updated, and the PE tag is being executed.
When the value pass compression test, there will be one new value being archived for the tag, and the PE tag is being executed again.

Thus my PE tag is calculated wrongly.

Is there any way that i can change my equation in order for me to get the correct calculation?

Thank you.

Sw

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I would start with a simpler conditional structure to narrow down the problem more easily (like a simple value assignment as opposed to your if-then structure). You may be able to get rid of the double-value on your PE by turning the compression on for your PE tag. If you have more questions you may want to contact OSIsoft Tech Support at techsupport@osisoft.com for a closer look.