Accessory apparatus, image-capturing apparatus, control method and storage medium storing control program

An accessory apparatus detachably attachable to an image-capturing apparatus, the accessory apparatus comprising:

• an accessory communicator configured to provide, with the image-capturing apparatus, three channels that are a notification channel used for providing a notice from the image-capturing apparatus to the accessory apparatus, a first data communication channel used for data transmission from the accessory apparatus to the image-capturing apparatus, and a second data communication channel selectively used for data transmission from the image-capturing apparatus to the accessory apparatus or data transmission from the accessory apparatus to the image-capturing apparatus;
• and
• an accessory controller configured to control data communication with the image-capturing apparatus through the accessory communicator,
• wherein:
• the accessory controller is configured to have a function of switching a setting of the second data communication channel between a first setting in which the data transmission from the image-capturing apparatus to the accessory apparatus is allowed and a second setting in which data transmission from the accessory apparatus to the image-capturing apparatus is allowed.

An image-capturing apparatus to which an accessory apparatus is detachably attachable, the image-capturing apparatus comprising:

• a camera communicator configured to provide, with the accessory apparatus, three channels that are a notification channel used for providing a notice from the image-capturing apparatus to the accessory apparatus, a first data communication channel used for data transmission from the accessory apparatus to the image-capturing apparatus, and a second data communication channel selectively used for data transmission from the image-capturing apparatus to the accessory apparatus or data transmission from the accessory apparatus to the image-capturing apparatus;
• and
• a camera controller configured to control data communication with the accessory apparatus through the camera communicator,
• wherein:
• the camera controller is configured to have a function of switching a setting of the second data communication channel between a first setting in which the data transmission from the image-capturing apparatus to the accessory apparatus is allowed and a second setting in which data transmission from the accessory apparatus to the image-capturing apparatus is allowed.

A control method for an accessory apparatus detachably attachable to an image-capturing apparatus, the method comprising the steps of:

• communicating with the image-capturing apparatus using three channels that are a notification channel used for providing a notice from the image-capturing apparatus to the accessory apparatus, a first data communication channel used for data transmission from the accessory apparatus to the image-capturing apparatus, and a second data communication channel used for data transmission from the image-capturing apparatus to the accessory apparatus;
• receiving, from the image-capturing apparatus through the notification channel, a first notice indicating completion of switching a setting of the second data communication channel from a first setting in which the data transmission from the image-capturing apparatus to the accessory apparatus is allowed to a second setting in which the data transmission from the accessory apparatus to the image-capturing apparatus is allowed in the image-capturing apparatus;
• switching the setting of the second data communication from the first setting to the second setting in the accessory apparatus;
• and
• communicating with the image-capturing using the three channels under a condition where the second communication channel is set for the second setting.

A control method for an image-capturing apparatus to which an accessory apparatus is detachably attachable, the method comprising the steps of:

• communicating with the accessory apparatus with three channels that are a notification channel used for providing a notice from the image-capturing apparatus to the accessory apparatus, a first data communication channel used for data transmission from the accessory apparatus to the image-capturing apparatus, and a second data communication channel used for data transmission from the image-capturing apparatus to the accessory apparatus;
• switching a setting of the second data communication channel from a first setting in which the data transmission from the image-capturing apparatus to the accessory apparatus is allowed
• to a second setting in which the data transmission from the accessory apparatus to the image-capturing apparatus is allowed,
• sending, to the accessory apparatus through the notification channel, in response to completion of switching from the first setting, a first notice indicating the completion of switching from the first setting to the second setting in the image-capturing apparatus;
• and
• communicating with the accessory apparatus using the three channels under a condition where the second communication channel is set for the second setting.