OK, so a Planck length is the small measurement possible. A Planck time is the time for something travelling at c to traverse a Planck length. So if we name Planck lengths as A, B, C, etc… and Planck times as 1, 2, 3… this object’s space-time coordinates would be
A1
B2
C3
etc
What about things NOT going c? Are they hanging around the same Planck length for more than one Planck time? Would
A1
A2
B3
B4
C5
C6
Be the coordinates of something travelling at c/2?
While it’s tempting to regard the Planck length as the “pixel size” of space, it doesn’t really work that way. Per Relativity, there is no background grid to spacetime. The Planck length is simply the scale at which, due to quantum mechanical considerations, it cannot be taken for granted that space is continuous. It’s more accurate to say that we cannot postulate anything happening at a smaller scale because our available theories break down.