Sensor controller, active pen, and communication method

An active pen that controls transmission of a downlink signal based on an uplink signal transmitted from a sensor controller, the active pen comprising:

• a pen tip;
• a pen pressure detector which, in operation, detects a pressure applied to the pen tip;
• an electrode provided at the pen tip;
• and
• an integrated circuit which, in operation, transmits a downlink signal including first identification data via the electrode after the active pen has been paired with the sensor controller, and in a case where an uplink signal including second identification data corresponding to the first identification data is received, controls transmission of a next downlink signal via the electrode based on the second identification data,
• wherein each of the first identification data and the second identification data is contact state data indicating whether the pen tip of the active pen is in contact with a touch surface, and
• wherein the integrated circuit in operation, compares the second identification data included in the uplink signal with the first identification data included in the downlink signal and controls transmission of the next downlink signal depending on a result of comparing the second identification data included in the uplink signal with the first identification data included in the downlink signal.