How do you determine when Labview is ready to send a new commnd to an Arduino board?

[hrh1818]

I would like to write a program where the rate at which the send receive interface can send write commnds to an Arduino board is the limiting factor that determines the pace of a program.   To do this the send receive interface would need to provide a ready signal.   The alternate approach of using a wait delay to determine the pace of a program does not produce optimum results.

I looked through the documentation but did not find any mention of a ready signal.  PerhapsI I looked in the wrong place.  Hence is a ready sigmal avaiable and where can I find information about it?

Howard

[Kristoff2]

hrh1818,

All of the LIFA VIs are blocking.  When you call a Digital Read VI for example LabVIEW send the digital read command to the Arduino and then sits and waits for the Arduinos response.  In the case where the Arduino does not respond with a requested value (like in the digital read case) the Arduino will return a status byte (eg 0 for no error).  So every VI that sends data to the Arduino also waits for a response from the Arduino before it returns.  This allow you to use standard data flow programming.

Let us know if you have more questions about this.

-Sam K

LIFA Developer

[hrh1818]

Thank uou ror yuour repy.

How do you know when a LIFA VI is blocking?  Can you query a VI to determine if a VI is in a blocking or non blocking state?  Or alternately can you place several commands in a queue and then have a VI automatically remove a command from the  queue and process the command when the VI leaves its blocking state?

Howard

[Kristoff2]

Howard,

It sounds like you are new to LabVIEW as these questions are not related to LIFA specifically.  I suggest you go through some example and tutorial for basic LabVIEW Programming and I think you will find the answers to these questions.  Check out these links.

http://www.ni.com/academic/students/learnlabview/

http://www.ni.com/gettingstarted/labviewbasics/

This one specifically discusses dataflow which is what you are asking about.

http://www.ni.com/gettingstarted/labviewbasics/dataflow.htm

-Sam K

LIFA Developer