Chapter3 PXISerial Hardware Installation, Verification, and Configuration
SerialHardware and Software for Win dows 3-22 ni.com
FIFO Buffer Size
The Receive FIFO size control sets the number of characters received in
theFIFO before the PC is interrupted to read the data. TheTransmit FIFO
size controlsets the maximum number of bytes written to the FIFO in a
block when the PC is interrupted to write the data. When you configure
FIFO settings, consider the following points:
•Youcan select larger FIFO buffer sizes to reduce the number of
interruptsyour PC r eceivesand therefore minimize system overhead.
•Ift ransfer rates are high, you can lower the Receive FIFO size value
to preventoverrun errors due to interrupt latency.
•Ifyour data transfer sizes are small and your Receive FIFO size value
isabove your data sizes, your system is less efficient. Therefore, set the
ReceiveFIFO size value below your data sizes.
Resources
To view theresource configuration dialog box for the selected port, click
on the Resources button. You cannot change these resources; they are
automatically assigned.