This article discusses using fast read mode on SmartReader Plus and OWL data loggers. Fast Read mode is supported by the SmartReader Plus and OWL loggers. This mode changes the logger’s onboard clock to allow faster sample rates (down to 0.04 sec on a SmartReader Plus and 0.2 sec on an OWL). To conserve power, the logger is forced into “Stop When Full” mode when Fast Read mode is selected. Any attempt to communicate with the logger will stop it recording. On SmartReader Plus loggers this mode will only record if a power source is connected to the communication port (either a computer port, battery pack or power supply providing sufficient current).