New to using /programming the UR. I am using a Keyence SZ Laser scanner and the configurable inputs on the UR to effect the reduced mode. The inputs have been configured for reduced mode, I can see the the I/O toggle on the UR control pendant when I walk in front of the scanner but the robot appears not to slow down, keeps running at the same speed. The log file indicates that the reduced mode had been activated although there is 'undefined' in the log entry line. The reduced mode safety configuration is set at 50% of normal speed???   

Maybe your robot isn't really running at normal max speed when it gets switched into reduced mode. Sometimes it's hard to see the reduction in speed because you don't realize that it's already running at close to the reduced speed. Program some movements (for test purposes) that are obviously fast and see if that has more of a noticeable effect or make the reduced speed something REALLY low like 250mm/sec.