An apparatus for communicating with a downhole tool includes a sensor body including at least two electrodes electrically insulated from one another and an external control device configured to engage the two electrodes. Detection circuitry connected to the two electrodes is configured to monitor an electrical status across the two electrodes, through the external control device, and upon detecting a change in electrical status that matches a predefined pattern, communicate a command to power management circuitry to alter a power status of the downhole tool.