USBDevice: controlTransferIn() method

{{APIRef("WebUSB API")}}{{SeeCompatTable}}{{SecureContext_Header}}{{AvailableInWorkers}}

The controlTransferIn() method of the {{domxref("USBDevice")}} interface returns a {{jsxref("Promise")}} that resolves with a {{domxref("USBInTransferResult")}} when a command or status request has been transmitted to (received by) the USB device.

Syntax

controlTransferIn(setup, length)

Parameters

• setup

  • : An object that sets options for. The available options are:
    • requestType
      • : Must be one of three values specifying whether the transfer is "standard" (common to all USB devices) "class" (common to an industry-standard class of devices) or "vendor".
    • recipient
      • : Specifies the target of the transfer on the device, one of "device", "interface", "endpoint", or "other".
    • request
      • : A vendor-specific command.
    • value
      • : Vendor-specific request parameters.
    • index
      • : The interface number of the recipient.

• length

  • : The maximum number of bytes to read from the device. The actual data is in the {{domxref("USBInTransferResult")}} in the resolved Promise.

Return value

{{jsxref("promise")}} that resolves with a {{domxref("USBInTransferResult")}}.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}