An elevator system constructed in accordance to one embodiment of the present disclosure includes an elevator car, a counterweight, a sheave assembly, a suspension rope, a compensation rope, a first optical sensor assembly and a controller. The suspension rope has a first suspension end coupled to the elevator car and a second suspension end coupled to the counterweight. The first compensation rope has a first compensation end coupled to the elevator car and a second compensation end coupled to the counterweight. The first optical sensor assembly can have a first optical sensor pair including a first emitter and a first receiver. The first emitter is configured to emit a first beam to be received by the first receiver. The first optical sensor pair is configured to detect interruption of the first beam by the first compensation rope. The controller controls movement of the elevator car based on the detected interruption.