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Contents
Programming For USB Device
Overview
Programmers Guide
Scenario
Data transfer
Synchronous Transfer
Asynchronous Transfer
Reading Descriptors
USB Support Routines And Structures
Common Procedures
UsbEnumerateDevices
OpenRapidUsb
IsRapidUsbOpened
CloseRapidUsb
Descriptors
UsbGetDescriptor
UsbGetDeviceDescriptor
UsbGetStringDescriptor
UsbGetConfigDescriptor
UsbFreeConfigDescriptor
UsbGetInterfaceDescriptor
UsbFreeInterfaceDescriptor
UsbGetEndpointDescriptor
Configure Device
UsbGetDeviceInfo
UsbUnconfigureDevice
UsbSelectConfig
UsbGetConfig
UsbSelectInterface
UsbGetInterface
UsbResetDevice
UsbGetBandwidthInfo
UsbCyclePort
Features and Status
UsbSetFeature
UsbClearFeature
UsbGetStatus
Vendor/Class Requests
UsbVendorRequestIn
UsbVendorRequestOut
UsbClassRequestIn
UsbClassRequestOut
Pipes
IsRapidUsbPipeOpened
UsbPipeOpen
UsbPipeClose
UsbGetPipeCount
UsbPipeGetInfo
UsbPipeDirectionIn
UsbPipeGetType
UsbTransfer
UsbTransferAsync
TRANSFER_COMPLETION_ROUTINE
UsbCancelTransfer
UsbPipeReset
UsbPipeAbort
Other
UsbGetPortStatus
UsbGetCurrentFrameNumber
USB Structures and Types
RDUSB_DEVICE_INFORMATION
RDUSB_PIPE_INFORMATION
RDUSB_PIPE_TYPE
RDUSB_BANDWIDTH_INFORMATION
UsbEnumerateDevices
Go to RapidDriver Main Page

Call this function before opening any device with OpenRapidUsb.

Language

Description

C/C++
UCHAR UsbEnumerateDevices ()
Delphi
function UsbEnumerateDevices () : Byte; stdcall
VB
Function UsbEnumerateDevices () As Byte


Return Value:
Return Value of this function is number of RapidUSB devices present in system.

Comments:
In most cases this function is called on application startup. It makes all arrangements for accessing other RapidUSB.dll functions. So call to OpenRapidUsb without preliminary call to UsbEnumerateDevices is not allowed.