Abstract: A system and method for communicating with a downhole tool. A downhole tool includes a downlink receiver and a command actuator. The downlink receiver receives control information, encoded in rotation of the tool, that controls operation of the tool. The downlink receiver includes a rotation sensor and a decoder. The rotation sensor senses rotation of the tool about a longitudinal axis. The decoder demarcates fields of the control information based on rotation state transitions sensed by the rotation sensor. The rotation state transitions are transitions between a rotating state and a non-rotating state. The decoder also decodes a control value for controlling the tool based on a duration of a field of the control information. The control value is wholly encoded in the field, and the field is encoded as a non-rotating state of the tool. The command actuator applies the control value to control operation of the tool.

Abstract: A system and method for communicating with a downhole tool. A downhole tool includes a downlink receiver and a command actuator. The downlink receiver receives control information, encoded in rotation of the tool, that controls operation of the tool. The downlink receiver includes a rotation sensor and a decoder. The rotation sensor senses rotation of the tool about a longitudinal axis. The decoder demarcates fields of the control information based on rotation state transitions sensed by the rotation sensor. The rotation state transitions are transitions between a rotating state and a non-rotating state. The decoder also decodes a control value for controlling the tool based on a duration of a field of the control information. The control value is wholly encoded in the field, and the field is encoded as a non-rotating state of the tool. The command actuator applies the control value to control operation of the tool.