LibUSBDeviceMBS.AttachKernelDriver(interfaceNumber as Integer)

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Re-attach an interface's kernel driver, which was previously detached using libusb_detach_kernel_driver().

This call is only effective on Linux and returns kErrorNotSupported on all other platforms.

This functionality is not available on Darwin or Windows.

Parameters:
interfaceNumber: the interface to attach the driver from

Lasterror is set:
0 on success
kErrorNotFound if no kernel driver was active
kErrorInvalidParam if the interface does not exist
kErrorNoDevice if the device has been disconnected
kErrorNotSupported on platforms where the functionality is not available
kErrorBusy if the driver cannot be attached because the interface is claimed by a program or driver
another error code on other failure

LibUSBDeviceMBS.BulkTransfer(endpoint as Integer, data as Ptr, Length as Integer, byref ActualLength as Integer, Timeout as Integer)

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Perform a USB bulk transfer.

The direction of the transfer is inferred from the direction bits of the endpoint address.

For bulk reads, the length field indicates the maximum length of data you are expecting to receive. If less data arrives than expected, this function will return that data, so be sure to check the transferred output parameter.

You should also check the transferred parameter for bulk writes. Not all of the data may have been written.

Also check transferred when dealing with a timeout error code. libusb may have to split your transfer into a number of chunks to satisfy underlying O/S requirements, meaning that the timeout may expire after the first few chunks have completed. libusb is careful not to lose any data that may have been transferred; do not assume that timeout conditions indicate a complete lack of I/O.

Parameters:

endpoint	the address of a valid endpoint to communicate with
data	a suitably-sized data buffer for either input or output (depending on endpoint)
length	for bulk writes, the number of bytes from data to be sent. for bulk reads, the maximum number of bytes to receive into the data buffer.
transferred	output location for the number of bytes actually transferred.
timeout	timeout (in millseconds) that this function should wait before giving up due to no response being received. For an unlimited timeout, use value 0.

Lasterror is set to:
0 on success (and populates transferred)
kErrorTimeout if the transfer timed out (and populates transferred)
kErrorPipe if the endpoint halted
kErrorOverflow if the device offered more data, see Packets and overflows
kErrorNoDevice if the device has been disconnected
another error code on other failures

LibUSBDeviceMBS.ClaimInterface(interfaceNumber as Integer)

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Claim an interface on a given device handle.

You must claim the interface you wish to use before you can perform I/O on any of its endpoints.

It is legal to attempt to claim an already-claimed interface, in which case libusb just returns 0 without doing anything.

Claiming of interfaces is a purely logical operation; it does not cause any requests to be sent over the bus. Interface claiming is used to instruct the underlying operating system that your application wishes to take ownership of the interface.

This is a non-blocking function.

Parameters:
interfaceNumber: the bInterfaceNumber of the interface you wish to claim

Lasterror is set:
0 on success
kErrorNotFound if the requested interface does not exist
kErrorBusy if another program or driver has claimed the interface
kErrorNoDevice if the device has been disconnected
a error code on other failure

LibUSBDeviceMBS.ClearHalt(endpoint as Integer)

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Clear the halt/stall condition for an endpoint.

Endpoints with halt status are unable to receive or transmit data until the halt condition is stalled.

You should cancel all pending transfers before attempting to clear the halt condition.

This is a blocking function.

Parameters:
endpoint: the endpoint to clear halt status

Returns:
0 on success
kErrorNotFound if the endpoint does not exist
kErrorNoDevice if the device has been disconnected
another error code on other failure

LibUSBDeviceMBS.Close

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Close a device handle.

Should be called on all open handles before your application exits.
Internally, this function destroys the reference that was added by Open on the given device.
This is a non-blocking function; no requests are sent over the bus.

LibUSBDeviceMBS.ControlTransfer(requestType as Integer, Request as Integer, Value as Integer, Index as Integer, data as Ptr, Length as Integer, Timeout as Integer) as Integer

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Perform a USB control transfer.

The direction of the transfer is inferred from the RequestType field of the setup packet.

The Value, Index and Length fields values should be given in host-endian byte order.

Parameters:

RequestType	the request type field for the setup packet
Request	the request field for the setup packet
Value	the value field for the setup packet
Index	the index field for the setup packet
data	a suitably-sized data buffer for either input or output (depending on direction bits within bmRequestType)
Length	the length field for the setup packet. The data buffer should be at least this size.
timeout	timeout (in millseconds) that this function should wait before giving up due to no response being received. For an unlimited timeout, use value 0.

on success, the number of bytes actually transferred is returned.

Lasterror is set to:
kErrorTimeout if the transfer timed out
kErrorPipe if the control request was not supported by the device
kErrorNoDevice if the device has been disconnected
another error code on other failures

LibUSBDeviceMBS.DetachKernelDriver(interfaceNumber as Integer)

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Detach a kernel driver from an interface.

If successful, you will then be able to claim the interface and perform I/O.
This functionality is not available on Darwin or Windows.

Parameters:
interfaceNumber: the interface to detach the driver from

Lasterror is set:
0 on success
kErrorNotFound if no kernel driver was active
kErrorInvalidParam if the interface does not exist
kErrorNoDevice if the device has been disconnected
kErrorNotSupported on platforms where the functionality is not available
another error code on other failure

LibUSBDeviceMBS.InterruptTransfer(endpoint as Integer, data as Ptr, Length as Integer, byref ActualLength as Integer, Timeout as Integer)

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Perform a USB interrupt transfer.

The direction of the transfer is inferred from the direction bits of the endpoint address.

For interrupt reads, the length field indicates the maximum length of data you are expecting to receive. If less data arrives than expected, this function will return that data, so be sure to check the transferred output parameter.

You should also check the transferred parameter for interrupt writes. Not all of the data may have been written.

Also check transferred when dealing with a timeout error code. libusb may have to split your transfer into a number of chunks to satisfy underlying O/S requirements, meaning that the timeout may expire after the first few chunks have completed. libusb is careful not to lose any data that may have been transferred; do not assume that timeout conditions indicate a complete lack of I/O.

The default endpoint bInterval value is used as the polling interval.

Parameters:

endpoint	the address of a valid endpoint to communicate with
data	a suitably-sized data buffer for either input or output (depending on endpoint)
length	for bulk writes, the number of bytes from data to be sent. for bulk reads, the maximum number of bytes to receive into the data buffer.
transferred	output location for the number of bytes actually transferred.
timeout	timeout (in millseconds) that this function should wait before giving up due to no response being received. For an unlimited timeout, use value 0.

The lasterror property is set to:
0 on success (and populates transferred)
kErrorTimeout if the transfer timed out
kErrorPipe if the endpoint halted
kErrorOverflow if the device offered more data, see Packets and overflows
kErrorNoDevice if the device has been disconnected
another error code on other error

LibUSBDeviceMBS.KernelDriverActive(interfaceNumber as Integer) as Boolean

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Determine if a kernel driver is active on an interface.

If a kernel driver is active, you cannot claim the interface, and libusb will be unable to perform I/O.

This functionality is not available on Windows.

Parameters:
interfaceNumber: the interface to check

Lasterror is set:
0 if no kernel driver is active
1 if a kernel driver is active
kErrorNoDevice if the device has been disconnected
kErrorNotSupported on platforms where the functionality is not available
another error code on other failure

LibUSBDeviceMBS.Open as Boolean

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Open a device and obtain a device handle.

A handle allows you to perform I/O on the device in question.

Internally, this function adds a reference to the device. This reference is removed during Close().

This is a non-blocking function; no requests are sent over the bus.

The last error to:
0 on success
kErrorNoMemory on memory allocation failure
kErrorAccess if the user has insufficient permissions
kErrorNoDevice if the device has been disconnected
another error code on other failure

LibUSBDeviceMBS.ReleaseInterface(interfaceNumber as Integer)

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Release an interface previously claimed with ClaimInterface.

You should release all claimed interfaces before closing a device handle.

This is a blocking function. A SET_INTERFACE control request will be sent to the device, resetting interface state to the first alternate setting.

Parameters:
interfaceNumber: the bInterfaceNumber of the previously-claimed interface

The lasterror:
0 on success
kErrorNotFound if the interface was not claimed
kErrorNoDevice if the device has been disconnected
another error code on other failure

LibUSBDeviceMBS.Reset

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Perform a USB port reset to reinitialize a device.

The system will attempt to restore the previous configuration and alternate settings after the reset has completed.

If the reset fails, the descriptors change, or the previous state cannot be restored, the device will appear to be disconnected and reconnected. This means that the device handle is no longer valid (you should close it) and rediscover the device. An error code of kErrorNotFound indicates when this is the case.

This is a blocking function which usually incurs a noticeable delay.

Lasterror is set:
0 on success
kErrorNotFound if re-enumeration is required, or if the device has been disconnected
another error code on other failure

LibUSBDeviceMBS.SetConfiguration(configuration as Integer)

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Set the active configuration for a device.

The operating system may or may not have already set an active configuration on the device. It is up to your application to ensure the correct configuration is selected before you attempt to claim interfaces and perform other operations.

If you call this function on a device already configured with the selected configuration, then this function will act as a lightweight device reset: it will issue a SET_CONFIGURATION request using the current configuration, causing most USB-related device state to be reset (altsetting reset to zero, endpoint halts cleared, toggles reset).

You cannot change/reset configuration if your application has claimed interfaces - you should free them with libusb_release_interface() first. You cannot change/reset configuration if other applications or drivers have claimed interfaces.

A configuration value of -1 will put the device in unconfigured state. The USB specifications state that a configuration value of 0 does this, however buggy devices exist which actually have a configuration 0.

You should always use this function rather than formulating your own SET_CONFIGURATION control request. This is because the underlying operating system needs to know when such changes happen.

This is a blocking function.

Parameters:
configuration: the bConfigurationValue of the configuration you wish to activate, or -1 if you wish to put the device in unconfigured state

The lasterror is set to:
0 on success
kErrorNotFound if the requested configuration does not exist
kErrorBusy if interfaces are currently claimed
kErrorNoDevice if the device has been disconnected
another error code on other failure

LibUSBDeviceMBS.SetInterfaceAltSetting(interfaceNumber as Integer, alternateSetting as Integer)

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
method	USB	MBS USB Plugin	18.1	✅ Yes	✅ Yes	✅ Yes	❌ No	Desktop, Console & Web

Activate an alternate setting for an interface.

The interface must have been previously claimed with ClaimInterface().

You should always use this function rather than formulating your own SET_INTERFACE control request. This is because the underlying operating system needs to know when such changes happen.

This is a blocking function.

Parameters:

interfaceNumber	the InterfaceNumber of the previously-claimed interface
alternateSetting	the AlternateSetting of the alternate setting to activate

The lasterror:
0 on success
kErrorNotFound if the interface was not claimed, or the requested alternate setting does not exist
kErrorNoDevice if the device has been disconnected
another error code on other failure