Memory Management

[jimhar66]

I have read some of the app notes regarding memory management under RT. The app notes indicate not using 'build array' functions within loops. Does this apply also to where a 'build array' is used inside a subVI? Or does the RT memory manager not get called in this case?

The routine we have currently calls two Analog Input read functions for two different AI boards, the data from each board (2D array) then is concatenated using 'build array'. The sample size for each channel is variable.

We have noticed increase in AI Buffer Read execution time when system is run over multiple days.

What about graphs, charts, do they cause any overhead even if not displayed?

Thank you in advance.

[Arun_V]

Hello Jim,

Irrespective where you use the build array, RT Memory Manager gets called. So it is a good idea to allocate memory to an array outside the loop and then just use other array functions to replace the data. In FPGA, you have to predefine the array size and there is pretty much no way around it.

As far as graphs and charts are concerned, there should not be any overhead if they are not displayed.

Regards,

Arun V
National Instruments