Question on Using FP Read with LabVIEW RT

[tmaxprt]

Hello   all

Two questions on using FP Read with cFP 20xx running LV RT 8.2 and using AI-100 module

1)  Is there a way to call FP Read once and have it read the data for ALL channels and return data using the scales that were configured for each individual channel in MAX?

If you try using FP Read with the "All" Channels property, you only get back the data scaled by whatever scaling factor was entered in MAX for "All".     I'd like to use the scaling factors for each channel and would rather not have to either call FP Read n number of times (for each channel) , nor implement scaling programatically...

2) Should I even be using FP Read in RT.?...The subvi has a build array function inside it!  Not good when dealing with RT....

[Elizabeth_S]

Hi Tmaxprt,

This issue was reported to R&D (#40A77GLF) for further investigation.  I'm sorry for the inconvenience but I would recommend scaling the channels programmatically for now.  Thanks for the feedback!

Regards,

Elizabeth S.

Applications Engineer

National Instruments

[tmaxprt]

Thanks for the response Elizabeth!

How about issue #2 (build array inside FP Read?)

[TreyB_NI]

Hi tmaxprt,

There is an initialize array inside the FP Read (FieldPoint v 5.01) but looking at memory allocation using Show Buffer Allocations (Tools>>Profile>>Show Buffer Allocation), it seems that the allocated array is passed by value to the calling VI.  Memory allocation is denoted by the black dot in the attached image.  If this weren't the case, indeed FP Read would not be possible in RT because there would be massive memory leaks and many FieldPoint Controllers have limited memory capacity.

I hope that helps!

Trey B
Applications Engineering
National Instruments