What is the function of Z1 in zelio screen for manual programming?

Z1, Z2, Z3, Z4 are inputs, they are the function keys on the bottom of the Zelio
Pressing 1st grey button from left means Z1 input =1
So, if those values are programmed into the customer logic manually done by him as in the below photo, then these inputs needs to be manually pressed to indicate that the input is 1