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.
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
USBInTransferResult
in the resolved Promise.
Return value
promise
that resolves with a USBInTransferResult
.
Specifications
Specification |
---|
WebUSB API # ref-for-dom-usbdevice-controltransferin |
Browser compatibility
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