what are the green up down arrows on the border of the while loops in dmy_srvr.vi?

[dingler44]

If I left click one of these arrows, they appear to be paired as both are highlighted. There's one up and one down on the while loop.
If I right click either, I'm presented w/ a menu w/ these options:
add element
remove all
create -> constant, control or indicator
What the heck are these little green up down arrows???(by the way they have no stem, really they're just triangles)

Jim

[BruceAmmons]

Jim,

These are shift registers. Basically, they store data from one iteration of the loop so it can be used in the next iteration of the loop. You can read more about them in the help file.

Bruce

[dingler44]

Ahhhhh thank you so much!