1.2.6.4.2 SRV_USI_Open Function
C
SRV_USI_HANDLE SRV_USI_Open( const SYS_MODULE_INDEX index )
Summary
Opens the specified USI service instance and returns a handle to it.
Description
This routine opens the specified USI service instance and provides a handle that must be provided to all other client-level operations to identify the caller and the instance of the service.
Precondition
Function SRV_USI_Initialize must have been called before calling this function.
Parameters
Param | Description |
---|---|
index | Index for the instance to be opened |
Returns
If successful, the routine returns a valid open-instance handle (SRV_USI_HANDLE Typedef).
If an error occurs, the return value is SRV_USI_HANDLE_INVALID. Error can occur
if the specified instance has been already opened.
if the instance being opened is not initialized or is invalid.
if there is an error opening the serial interface (USB CDC instances only)
Example
SRV_USI_HANDLE handle;
handle = SRV_USI_Open(SRV_USI_INDEX_0);
if (handle == SRV_USI_HANDLE_INVALID)
{
// Unable to open USI instance. Maybe it is not initialized
}
Remarks
The handle returned is valid until SRV_USI_Close is called.