Disable Safety Gate error under certain conditions

I assume this is a KUKA robot? What generation, controller model, and KSS version?

For a basic robot with standard safety, there's really no option here -- if the robot is in AUT or EXT mode, and the Operator Safety (safety gate) signal is lost, the robot faults. Period. Any way of "bypassing" this would violate safety requirements.

If the robot has SafeOperation installed, you might be able to engage Standstill Monitoring and "freeze" the robot without generating a fault when the light screen is violated. But, this creates a potential serious safety hazard: if someone is inside the safety perimeter, and someone or something else resets the light screen, you now have a person inside the perimeter with a live robot and no protection. You would need an interior fence, area scanner, or something similar that can prevent that situation in order to meet safety standards.

you may consider muting sensor. of course it need to be safety rated (same or higher than light barrier).

so to activate muting function, program robot to go to safe place (confirmed by muting sensor), indicate that operator may approach. when operator is done and leaves area, have the robot move again.

muting sensor would be wired/programmed in parallel with light barrier (OR function).

if operator completes action while robot is at safe location, muting sensor would bypass signal from light barrier and everything would be fine. no operator safety acknowledgment would be needed.

if for some reason robot moves away from safe location, while operator is in the danger zone, both muting sensor and light barrier would be tripped and robot would see it as a violation of operator safety (and stop). in this case operator safety acknowledgement would be required.

of course you need to do a proper risk assessment (speeds/distances) to meet the standards.