Online Development Notebook > Index > Programming Overview > DLL Commands > DeviceValid

DeviceValid - Return a device-present indication

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Description:

This is a USBm.dll function that returns indication of validity from a USB device.

Command Syntax:

true⁄false USBm_DeviceValid( device )

The USBm_DeviceValid function syntax has these parts:

Remarks:

Note: USBm_DeviceValid always returns TRUE if the device is valid, otherwise FALSE.

VB Declaration (USBmAPI.bas)

Public Declare Function USBm_DeviceValid _     Lib "USBm.dll" _         (ByVal device As Byte) _     As Integer

VB Example

Dim result As Integer     result = USBm_DeviceValid 3

This code fragment shows that result is loaded with TRUE if device three exists, or with FALSE if the device does not exist.

C Prototype

int USBm_DeviceValid( unsigned char device );

C Example

RobotBASIC

usbm_DeviceValid(ne_DeviceNumber)

Returns true if the device number refers to a connected and active device. False otherwise.

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Hardware:  U401 USB Interface    U421 USB Interface   U451 USB Interface

Programming:  USBm DLL Programming    Download Files

Application Notes:  U4x1 Application Notes    Misc Applications and Information    FAQ

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