Set up time for ni 6501 to control relay

Question

Hi,all
I have made great progresses with your help. Right now I know how to control the relay using NI 6501.
Furthermore,  I try to set up a time period (after 2 hours) and then let NI 6501 switch on the relay.
What kind of example can I refer to?
Another control is when pressure data is low to 1mtorr, then switch on relay.
If there are some similar examples I can refer to, it will be helpful for me programming
Thanks
Solved!
Go to Solution.

Answer 1

Here is an example of how to control your valves:
This example is not ideal.  For example, the Write to Spreadsheet File is called each loop iteration just to write only one value.  This is a waste.  It would be better to collect all your data into an array (use a wire to loop edge with indexing on), and call the Write function once with an entire array of data.  I will leave it up to you to do this.  You could use the practice.  Another thing is that a lot of local variables are used.  Also not ideal.
Also, a state machine architecture would serve this purpose much better.  First state would be similar to the first sequence frame.  Second state would be like the while loop.  And so on...  See if you can implement this code in a state machine.  One advantage would be to control each stage of the code in an orderly manner.  Another advantage would come if you ever had to change the order of execution, or insert code in between states.  Just add a new state and/or change the next state pointer.  Local variables can be replaced by shift registers in a state machine, leading to the code being easier to read.  See if you can do this.
- tbob
Inventor of the WORM Global