---
title: RxFreeSpaceAvailable
framework: serialdriverkit
role: symbol
role_heading: Instance Method
path: serialdriverkit/iouserserial/rxfreespaceavailable
---

# RxFreeSpaceAvailable

Notifies your driver that buffer space is available for your device’s data.

## Declaration

```occ
virtual void RxFreeSpaceAvailable();
```

## Discussion

Discussion Override this method and use it to read data asynchronously from the device’s serial port. When you finish reading the data, call the RxDataAvailable method to let the system know the data is ready.

## See Also

### Transmitting and Receiving Data

- [RxDataAvailable](serialdriverkit/iouserserial/rxdataavailable.md)
- [TxDataAvailable](serialdriverkit/iouserserial/txdataavailable.md)
- [TxFreeSpaceAvailable](serialdriverkit/iouserserial/txfreespaceavailable.md)
- [RxError](serialdriverkit/iouserserial/rxerror.md)