Electric window covering, electric window covering system, and window covering alignment method

A first electric window covering, comprising:

• an upper rail;
• a lower rail disposed below the upper rail and driven to move relative to the upper rail between an upper limit position and a lower limit position of the lower rail;
• a lower rail driving assembly comprising a lower rail motor and a lower rail encoder, wherein the lower rail encoder senses rotation of a lower rail motor to generate a lower rail encoding signal representing a current position of the lower rail;
• a control device electrically connected to the lower rail motor and the lower rail encoder, the control device configured to control the lower rail motor to drive the lower rail to move and to receive the lower rail encoding signal from the lower rail encoder;
• and
• a power supply unit electrically connected to the lower rail motor, the control device, and the lower rail encoder;
• wherein the control device, upon receiving a specific remote control command, transmits a first alignment packet to a second electric window covering and receives a second alignment packet from the second electric window covering, and controls the lower rail motor to align the lower rail based on the first alignment packet and the second alignment packet, wherein the first alignment packet includes at least information about the current position of the lower rail of the first electric window covering when it is stopped or stationary, and the second alignment packet includes at least information about a current position of a lower rail of the second electric window covering when it is stopped or stationary.