Eberles PLS help

Trying to wrap my head around an Eberle PLS 511 program. I have a register 700 describes as EXOR/ZS/inc.dec counter. Looks like it's called up (represented as a coil) in a bunch of rungs. (See attached example). Can anyone explain how its works?

Looks like it used as a buffer?

I've never heard of Eberles PLS. But from what I gather, 770 is a counter and when the setpoint is reached, the 770 bit goes high. It looks to me like they are using it here to delay outputs for safety. This is just a guess