How does this program group and cluster these button values into an array?

Question

In the attached program, there are 6 buttons in a cluster and 1 individual button. These buttons control a bunch of different relays to control power to different components of a single device. Right now the program works in that I can control the 6 buttons, the LED turns on in the board and the power is being transmitted. What I do not understand is how it is doing this.  I ran the program with the highlight execution on and at the start of the read from array component, if say I pressed button 6 and hit ok, it reads #6, where did these get defined and labled? and if i wanted to add another button/relay how do i do this? If someone could explain step by step how this is grouping the relays on the board into an array and then controling them I would really appreciate it. Thanks.
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Cluster to Array.vi ‏85 KB

Answer 1

The #6 your seeing is the number of elements in the array not a value for the array. 
Now for some deeper explainations.   From the code it appears that exactly 1 of 6 valves may be used and an additional valve may be in one of two possible states.
When the program is run the cluster of buttons is initiallized to all False.  and we enter the outer while loop where a sequence structure starts.  In the first frame of the sequence we initiallize a shift register to hold the current value of "Buttons." and this loop runs unthrottled (Add a wait for next ms multiple to this loop to prevent using 100% of the CPU!) 
For each iteration the buttons are read and if a change has occured to any value buttons that were previously True are reset to False to prevent opening more than one valve.
When the user presses OK or stop- the current "Buttons" value is passed to the next frame.  This frame convertsthe 7 boolean values to a integer where each valve is controlled by a seperate bit of the integer (Isolation is bit 6 and bits 0-5 each control a mixing valve)
Now I'd strongly recommend reworking the DAQmx calls- it is pointless to initiallize the task each time you want to use it- Create the task in the initialzation case and wait until the user exits to destroy the task.  And well a sequence structures are frowned on- (there are better ways to do this)
As far as adding a relay- right now the relays are associated to the hardware by their index position in the cluster (element 1 = bit 0 etc....) to add a new valve you would need to decide what bit you would use to drive it and code in that bits' value to write a 0 in that bit.  (hint the 40 constant is realy 0x40 right-click>visable items>show radix )
Let me know if you need further elaboration
Jeff