The ProLine Dynamic Timer allows companies to monitor back up on production lines.  Set the value for the timer.  Once the photo-sensor is blocked for that time, the output contacts will close allowing you to light a lamp, sound a buzzer, or signal other equipment.  Choose from Hours/Minutes or Minutes/Seconds.  Includes a 2" range diffuse sensor with magnet mount and 3m cable as well as an output cable with flying leads (N.O. Contact).  Other sensor inputs are available as well as cable extensions.