data delay buffer

[virtualbruno]

Hello,

I am looking for a simple way to create a variable length, slow speed, data buffer. So far I have not found something suitable in the examples. The application is simple: I need to delay real-time wind data (speed, direction from two sources) by the amount of time it takes for the measured wind to arrive at the turbine (depends on the physical distance between sensor and turbine).

I just have a basic Labview so I don't have access to "Delay Signal.vi".

Just some hints, I will work out the details.

[altenbach]

There are many ways to do this. Can you attach a simplified version of the code you have so far?

What form is the data in? (scalar, dynamic, array, etc?).

What is "variable lenght"? (variable delay time? variable # of buffered samples? both?) Is the lenght fixed for the duration of the run or can it vary dynamically?

Some ideas:

• An action engine maintaining the buffer in a shift register?
• Queues.
• "Collector" express VI.

[virtualbruno]

Thanks for the quick reply.

Can you attach a simplified version of the code you have so far?  >> I am new to LV and just working on examples for now until the concept is complete. I just completed basic serial communications with theinstrument and am starting signal processing.

What form is the data in? (scalar, dynamic, array, etc?). >> 2 or more (in groups of 2, ~8 max) Scalar values in Engineering units, fixed for the application.

What is "variable lenght"? (variable delay time? variable # of buffered samples? both?) Is the lenght fixed for the duration of the run or can it vary dynamically?  >>The length of the buffer depends on the physical distance, a contant at run time AND the actual speed, a continous scalar, reduced to integer, variable within a pre-determined range. The entry and exit data processing speed will be the same once the buffer is filled. In other words, the buffer width (# of wariables) is fixed for the VI but the length (time for the wind to arrive) must be able to adjust to the (wind) speed so that the correct speed is used with the turbine power readings.

I am now working with the Queue Basics.vi sample. It looks like it will do the job if several queue can be locked ogether to form an array.