Formatted I/O Services

The Formatted I/O Services perform formatted and buffered I/O for devices. A formatted write operation writes to a buffer inside the VISA driver, while a formatted read operation reads from a buffer inside the driver. Buffering improves system performance by having the driver perform the I/O with the device only at certain times, such as when the buffer is full. The driver is then able to send larger blocks of information to the device at a time, improving overall throughput.

The buffer operations also provide control over the low-level serial driver buffers. See Controlling the Serial I/O Buffers for more information on that topic.