Communication system and camera system

A camera system comprising:

• an interchangeable lens;
• and
• a camera body, wherein
• the interchangeable lens includes a lens controller which provides a first data communication circuit and a data transmission circuit,
• the camera body includes a body controller which provides a second data communication circuit and a data reception circuit,
• the lens controller which transmits and receives data using the first data communication circuit through a first communication line, and transmits data using the data transmission circuit through a second communication line,
• the body controller which transmits and receives data using the second data communication circuit through the first communication line, and receives data using the data reception circuit through the second communication line, and
• the body controller switches and selectively executes one of:
• a reception mode for receiving data from the lens controller using the second communication circuit and the data reception circuit through the first communication line and the second communication line, and
• a transmission/reception mode for transmitting data to the lens controller using the second data communication circuit through the first communication line and receiving data from the lens controller using the data reception circuit through the second communication line.

A camera system which comprises a camera body, and an interchangeable lens, the camera system comprising:

• a first communication line which connects between a first data communication circuit of the interchangeable lens and a second data communication circuit of the camera body with a direction of the communication switchable;
• a second communication line which connects between a data transmission circuit of the interchangeable lens and a data reception circuit of the camera body in a predetermined communication direction;
• and
• a controller which controls communication through the first communication line and the second communication line, and
• the controller includes:
• a first communication state of matching the communication direction through the first communication line and the communication direction through the second communication line, and performing unidirectional communication between the interchangeable lens and the camera body using both of the first and the second communication lines, and
• a second communication state of differing the communication direction through the first communication line and the communication direction through the second communication line, and performing bidirectional communication between the interchangeable lens and the camera body using both of the first and the second communication lines.