New Programmer
 

Hi,I'm a new programmer and I was following a tutorial and it kept using a certain vi,but i couldn't recognize it or find it in the tool pallet.Can someone tell me what it is and where to find it

Re: New Programmer
 

Feedback node. Located in the Programming -> Structures pallet.

Re: New Programmer
 

That is called a feed back node. It stores the last value fed in so that you can compare a variable or value to itself. It is found in the Structures pallet towards the bottom right.

Re: New Programmer
 

Thank You

Re: New Programmer
 

Oh one more.Sorry for the nuisance

Re: New Programmer
 

No need, that's why we're all here; to help.

That is a Boolean> True/False. Depending on which letter, T or F, has green behind it tells you which is running. (i.e. Green-background T means it's running True).

Re: New Programmer
 

The feedback node is found in the Structures palette. It points from right to left by default. The diamond underneath it is how older versions of LabVIEW marked the initializer terminal; this year it looks like an asterisk which becomes a cursive i when wired.

The green T/F is a Boolean constant from an older version of LabVIEW. It would alternately highlight the T and the F when clicked on. LabVIEW 2012 instead displays it as a single square with either a T or an F in it. You'll find the T and F constants in the Boolean function palette.

Re: New Programmer
 

Now I'm trying to insert a process much like this which will set a servo to 90 activate a relay forward and then set both of them back to their natural position
but it seems to be running too fast and starving the drive system any pointers

Re: New Programmer
 

Unless we see what you're actually doing, we won't be able to give much in the way of help. Show us your code, not the example you're emulating.

Re: New Programmer
 

oh sorry yes here

Re: New Programmer
 

If you place the code into teleop, it will prevent teleop from running frequently enough. Try moving it to Periodic tasks.

Greg McKaskle

Re: New Programmer
 

I can't be the only LabVIEW developer that despises the use of the feedback node, can I? IMO, while feedback nodes *can* make a diagram cleaner, they actually make it *harder* to understand, as compared to using the equivalent shift register.

Re: New Programmer
 

I attempted this and it still says it is starving the drive loop

Re: New Programmer
 

You can attach your vi's directly to a post.
Show us your Teleop.vi & Periodic.vi, and any other vi you might have added code to.

The code you posted looks fine as long as it's in Periodic Tasks.vi (it would not work in Teleop).

Re: New Programmer
 

I also learned LV long before there were shift registers and in many ways prefer them, but I now use both, typically for different things. I really like the compare to last with a shift register, but otherwise typically use shift registers.

Greg McKaskle