Oscillate value of an attribute

Hey there

I'm new to Max, so please excuse my newbie question. After googling, I still don't manage to find a proper solution.

I have this threshold attribute for jit.gl.pass and want it to change like an Oscillator from 0 to like 0.5 in an fixed interval, so that I can manipulate the interval and the output (0-0.3, 0-0.8, etc.).

I tried stuff with phasor and other oscillators, but direct linking it to the threshold attribute didn't work. Can somebody nudge me to the right direction?

Thank you in advance and have a nice day!

Cedric