Data "ticking" problem with data memory function. help!

I am trying to write a simple "data memory" function with "data dam" component.

you can see it in the attach files

which can allow you to restore a value when the input boolean is "true" and read a saved value when input boolean is "false"

it seems working good till I link the output to a "data recorder"

the number is persistent but keeping refresh every 0.5 second.

this cause a huge trouble that all the component which inherit the output

recalculates every tick.  

is there a way to make data steady,only refresh when a different value input?