USBDevice: controlTransferIn() method
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is available in Web Workers.
The controlTransferIn() method of the USBDevice interface returns a Promise that resolves with a 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
USBInTransferResultin the resolved Promise.
Return value
promise that resolves with a USBInTransferResult.
Specifications
| Specification |
|---|
| WebUSB API # ref-for-dom-usbdevice-controltransferin |