The CircleScout S utilizes periodic GPS reporting and satellite communication to track the position of your center pivot. It also can tell you when your pivot starts or stops.
The CircleScout S consists of a power supply and satellite modem. The power supply is designed to be mounted inside the end tower box of the pivot. The satellite modem is designed to be magnetically mounted to the pivot structure outside the tower box.
The power supply is designed to parallel off the forward and reverse run ~ 120 VAC control circuits. When it sees this signal go from low to high, it triggers an event that the pivot started. When it sees this signal go from high to low, it triggers an event that the pivot stopped.
When the pivot starts walking, the rechargeable battery in the power supply begins to charge and will usually fully charge in 5 minutes. When the pivot stops walking; the rechargeable battery maintains power to the satellite modem, which then transmits the event code that the main AC power supplied by the pivot has dropped out. The battery will attempt to transmit this stop code for up to 1 hour.
Because of satellite communication (which isn't susceptible to dead spots like cellular communication), the CircleScout "S" is an extremely reliable pivot monitoring solution. Likewise, the resilient battery design dramatically increases the reliability of stop messages successfully transmitting.