Setting voltage sensitivity on NI 6581

[steinhagelvoll]

Hello,

I've got the following system:

https://www.ni.com/en-us/support/model.ni-6581.html

The specification says:

Selectable voltages of 1.8, 2.5, and 3.3 V or external reference voltage (1.8 to 5.5

How do I select these voltages? The manuel uses somekind of read write control with an unnamed reference.  I cannot find this reference. Is the a possibility to set this on the FPGA's vi?

Greeting

Matthias

[Julien_31]

hello,

I don't really know that device, but I have ever used some RIO devices, so I can try helping you.

The manuel you are talking about shows this image :

This is a "Read/Write Control" node which can be found in the "FPGA Interface" palette. This palette is available when you edit the diagram of the RT code (I said : "RT code"...not "FPGA code").

The reference you mentioned in your message is a FPGA VI reference : you can get this reference by using "Open FPGA VI Reference" function, in the same palette ("FPGA Interface", available from RT code diagram).

Those tools allow you to control the execution of your FPGA VI from the RT part of your code : you can set control values (controls placed on the FPGA VI front-panel), run this FPGA VI, retrieve data from DMA FIFO, etc...

So, from this little screenshot, we can assume that the developer put 2 commands on the FPGA VI front-panel. The respective labels for these 2 controls are "Power Supply (Connector A)" and "Internal Power Supply Voltage".

Then, from RT code diagram, he opened a FPGA VI reference, and then changed the value of these 2 controls by using "Read/Write" Control node (before or after running the FPGA VI with an "Invoke Method" node, also available in the palette).

But...there's no screenshot showing how these 2 parameters are modified by FPGA. I guess that in the FPGA VI, an "FPGA I/O Property" node gives an access to power supply settings.

In the manual, it is said :

"Use the NI Example Finder to find several NI FlexRIO device power setting examples"...Beyond my explanations that probably sound a little bit compliicated, I think that it will be the best way to find an answer to your question ! 😉

Julien

[Chris13]

Hello steinhagelvoll,

as far as I can see it in the manual of this device, there is a table on page 8. In this table, "Table 2", you can see the values for the voltage and the integer value you can input to choose a value for the voltage (0 is 3.3V ,1 is 2.5V and 2 is 1.8V).

The rest I found out is just like Julien_2831 said.

There is also a detailed help page in LabVIEW for this topic. Just open the LabVIEW Help and type "6581" to find general information about the settings of your device. For the read/write control of the FPGA interface palette, type "read/write control" - the first result explains how the control works.

There are also some example VIs, please open the Example Finder and type "6581R", then open the first result. In the block diagram of this example VI, you can see how the controls are used to set the supply voltage. I think this is a lot better than the small screenshot in the manual.

Link to manual I read:

https://www.ni.com/docs/en-US/bundle/ni-6581-6581b-getting-started/page/getting-started.html

I hope these tips were helpful to you, please reply if it works 😉

Cheers,

DerWilly