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FIFO Buffers
FIFO buffers are present on the 16550-compatible UARTs—one for the
transmitter and one for the receiver. The Receive Buffer control sets the
number of characters received in the FIFO before the PC is interrupted to
read the data. The Transmit Buffer control sets the maximum number of
bytes written to the FIFO in a block when the PC is interrupted to write
the data.
The built-in ports on PXI RT controllers and the PCI, PXI, and PCMCIA
plug-in serial boards have configurable FIFO settings. Use the
Advanced
tab in MAX to configure your FIFO settings. When you configure FIFO
settings, consider the following points:
You can select larger FIFO buffer sizes to reduce the number of
interrupts your PC receives and thereby minimize system
overhead.
If transfer rates are high, you can lower the Receive Buffer value to
prevent overrun errors due to interrupt latency.
If your data transfer sizes are small, and your Receive Buffer value
is above your data sizes, your system is less efficient. For
maximum efficiency, set your Receive Buffer value such that your
data transfer size is a multiple of that value.
Summary of Contents for ENET-232 Series
Page 1: ......
Page 5: ...Using Help Conventions Navigating Help Searching Help Printing Help File Topics ...
Page 21: ...Serial Hardware Overview PCI Kits PXI Kits USB Kits ENET Kits ExpressCard Kits PCMCIA Kits ...
Page 24: ...PCI 485I RS 485 two port isolated RS 485 four port isolated ...
Page 27: ...PXI 8423 RS 485 two port isolated RS 485 four port isolated ...
Page 63: ...Save Pending Changes To save your changes to this item click Save ...
Page 98: ...0 LPVOID l_SerialInterface sizeof l_SerialInterface LPDWORD l_ByteCount NULL ...
Page 127: ...2 PORT LEDs USB Serial Hardware LEDs ...
Page 139: ...Connecting the Cables to a Four Port PXI Serial Board ...
Page 141: ...67 58 50 41 33 24 16 7 TXD 9 RI 9 ...
Page 167: ......
Page 169: ......
Page 171: ......
Page 181: ...How many serial ports can I have on my machine You can have up to 256 serial ports ...
Page 201: ...Glossary Prefixes Symbols A B C D E F G H I K L M P R S T U V ...
Page 203: ...Symbols degrees ohms percent ...
Page 204: ...A A amperes ANSI American National Standards Institute ...
Page 205: ...B b bits B bytes baud bits per second bps bits per second ...
Page 208: ...E EIA Electronic Industries Association EMI electromagnetic interference ENET Ethernet ...
Page 209: ...F FCC Federal Communications Commission FIFO First In First Out ft feet ...
Page 210: ...G G ground ...
Page 211: ...H HSI handshake input HSO handshake output Hz Hertz ...
Page 213: ...K Kbaud kilobits per second ...
Page 214: ...L LED light emitting diode ...
Page 215: ...M m meters MB megabyte ...
Page 216: ...P PC personal computer PCI Peripheral Components Interconnect ...
Page 218: ...S s seconds SCSI Small Computer Systems Interface ...
Page 220: ...U UART Universal Asynchronous Receiver Transmitter ...
Page 221: ...V V volts VDC volts direct current VXI VME eXtensions for Instrumentation ...