The Probe 100 is useful in identifying types of power disturbances that are on the 110 volt AC line. It is like taking a snapshot of specific power problems. If you are having a problem with a computer system or peripheral, the Probe can be plugged into the same circuit and left for a period of time. When a problem is experienced with the equipment, immediate checking of the Probe's LEDs will indicate the worst case power problem. If none of the LEDs are illuminated then the problem may be with the hardware. The LEDs that are illuminated indicate the types of disturbances that may be affecting the equipment. The LEDs on the Probe "latch" in the ON position when the device receives a disturbance. Comes with the Probe Communications Software. This software facilitates the accumulation of the AC line voltage and Disturbances as they are broadcast by the Probe 100+. These can then be plotted or stored on the PC for future analysis. The software is capable of generating voltage DATALOG charts and disturbance PIE CHARTS from the received data.