Read() vs MemoryOptimizedReadMultiPoint() - Resistance reading quicker, Capacitance slower

[Gazlar]

Just running an experiment on various ways to get a fast reading from my NI-4072 and was just wondering if anyone can explain the following.

I am testing about 80 components on a PCB. These components are resistors, capacitors, diodes and transistors.

I do 2 loops.

First loop checks all the components using the Read() fuction.

Resistors = 4 seconds

Capacitors = 4.5 seconds

Didoes = 1.43 seconds

Transistors = 0.38 seconds 

Then I repeat then loop and use MemoryOptimizedReadMultiPoint(). I have the sample count to 8.

Resistors = 2.3 seconds

Capacitors = 15 seconds

Didoes = 0.45 seconds

Transistors = 0.34 seconds 

Just wondering why everything is read much faster, except capacitors which take a massive hit.

[Kiwi007]

Hi Gazlar,

So you are using a read function which varies in the time it takes dependent on what you are measuring?

Could you provide me some code and a diagram of how your PCB, and how the NI-4072 is connected

Daniel

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[Gazlar]

No what I am saying is that if I use the Read function to read some resistors, it takes about 4 seconds to read all of them.

If i use the MemoryOptimizedReadMultiPoint function, it does it in almost half the time.

But, for capacitors,MemoryOptimizedReadMultiPoint is slower. Just wondered why.

sorry, can't provide a drawing of PCB as its to do with my company.

[Kiwi007]

Have you set the maximumTime paramater? By default the device will choose

 http://zone.ni.com/reference/en-XX/help/375591C-01/ninetdmmfx40ref/html/m_nationalinstruments_modula...

Daniel