Chapter2 PCISerial Hardware Installation, Verification, and Configuration
©NationalInstruments Corporation 2-9 SerialHardware and Software for Windows
Use FIFO Buffers
FIFOb uffers are present on the 16550-compatible UARTs—one for the
transmitterand one for the receiver. The Receive Buffer control sets the
numbero fc haractersreceived in the FIFO before the PC is interrupted to
read the data. The Transmit Buffer control sets the maximum number of
byteswritten 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 Buffer value to
preventoverrun errors due to interrupt latency.
•Ifyour data transfer sizes are small and your Receive Buffer value is
aboveyour data sizes, your system is less efficient. Therefore, set the
ReceiveBuffer value below your data sizes.
Restore Defaults
Toreset the fields totheir default values at any t ime,click on theRestore
Defaults button.
Windows Me/9x
Install the Software
Before you install your serial hardware, complete the following steps to
installthe NI-Serial software for Windows Me/9x:
1. Select Start»Settings»Control Panel.
2. Double-clickon the Add/Remove Pro gramsicon. TheAdd/Remove
Programs dialog box appears.
3. ClickontheInstallbutton.
4. When prompted, insert the NI-Serial Software for Windows
2000/NT/Me/9x CD,andclickontheNextbutton.
5. Whenprompted, click on the Finish button to install the program files
fromflop pydisks o r CD-ROM.
6. The setup wizard begins.The setup wizard gu ides you through the
necessary steps to install the NI-Serial software. Toexit the setup
wizard ata nytime, click on the Cancel button.
7. Ifyou need to install your hardware, or if this is your first time to install
the NI-Serial software for WindowsMe/9x, skip to the next section,
Install the Hardware. Otherwise, continue to step 8.