reading data

[hofer]

Iam having a VI with upeer limit and lower limit.Iam reading data from DAQ card,if the data which iam is above or below the upper limit,them alarm set is indicated otherwise alarm clear is indicated.The alaram set and alarm clear is stored in a file along with date and time,when ever I run the VI.My problem is,if the value which iam reading is out of range then alaram set shold be shown in the file only once.but in my VI it is showing alarm set or alaram clear continuously until the other thing happens.How to over come this problem.

my exact question is ,in the saved file alarm set or alarm clear should be displayed only once but not for each and evry value which iam reading.here iam attaching my vi.

[ManuelW]

hello

I change your example a littel bit ( I use case structure and shift regiser)
I hope it answered your question.

Wielander

[altenbach]

There are two ways to interpret your question:

(1) You want all data saved to file, but the alarm related text should only show whenever it changes (blank otherwise).
(2) You only want data saved to file whenever the alarm changes.

In both cases, a line should probably get written unconditionally the first time the loop iterates.

I have implemented case (1) with a few small modifications to your VI. If you want case (2) behavior, you should place the case structure where indicated with the green frame.