how do you create array of enums for transitions in a state machine?

[RavensFan]

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@dav2010 wrote:

What is the indicator you have in the lower left corner labelled "Current State"?  Where is this icon found on the pallette?  I cannot reproduce this one.  Also, what data type is coming out of the shift register?  Is the state label a text string?  I can't get a string indicator to work to display the state from the shift register.

Thanks,

Dave

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It is an enum indicator.  Just right click on the wire and pick Create Indicator.  Enum is the datatype.

A state machine implies an architecture where you are in a certain state, and you may go to one or more different states as a function of different conditions and where you are now.  What you are describing sounds like it doesn't matter where you are now, it is strictly based on a set of conditions.  In that case, you just need to set up your decisions at the beginning of the while loop and have that drive a case structure.  You won't need to have the shift register which is a key feature that makes a state machine a state machine.

If you have 2 inputs (A, B) and 3 conditions for each (Low, High, OK) you have have 3x3 decision tree like you said.  Create a 2-D array of 3 rows and 3 columns.  Populate it with enums.  Have the A condition index out a row, and a B condition index out a column.  The resulting enum will determine which case of the case structure to run.

[dav2010]

Thanks RAvens fan, I will try what you suggested.  It sounds easier than the state machine.  I'm sure I'll have more questions once I get into it a bit.  Thanks for your help. 

Actually, I can reduce the matrix to a 1-d matrix of 9 elements instead of a 2-d matrix of 3x3 elements. Would you expect the 1-d to be a better approach than the 2-d, or are they the same in your mind?

Dave

[RavensFan · Accepted solution]

I think 2-D is better.  Since you have 2 different inputs with 3 possible cases, that sounds exactly like a lookup table to me.  Read the value of one input across and the other input down.  You've got a value that tells you which case of a case structure to execute.