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USB-232 Transceiver Control
The USB-232 two and four-port hardware supports both DTE and DCE
transceiver modes. By default, the RS-232 transceiver mode is forced to
DTE, but you can adjust this in two ways:
Use the
Advanced
tab in MAX. To set the transceiver mode to be
used whenever a port is opened, select the desired mode from the
transceiver mode pull-down menu.
Change the transceiver mode programmatically by making a
DeviceIoControl function call to the serial driver.
The following table describes the RS-232 modes.
RS-232 Modes
RS-232
Mode
Description
Force
DTE
(Default)
The transceiver is forced into DTE mode
Force
DCE
The transceiver is forced into DCE mode
Auto
232
The transceiver automatically switches between DTE and DCE
modes about four times a second until a valid RS-232 signal is
detected
Note
When using Auto232, if you connect two serial ports set to
Auto232, or if valid RS-232 signals are present in both modes, the
final mode may be either DTE or DCE.
Note
A valid RS-232 signal is defined as at least one valid RS-232
voltage detected on any receiver pin (RXD, CTS, DSR, RI, or
DCD).
The USB-232 hardware also allows you to set and retrieve the state of
the of the Ring Indicate (RI) and Data Carrier Detect (DCD) lines along
with the Transceiver Mode.
Setting the RS-232 Transceiver Mode with DeviceIoControl
Setting Ring Indicate (RI) and Data Carrier Detect (DCD) with
DeviceIoControl
Содержание ENET-232 Series
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Страница 5: ...Using Help Conventions Navigating Help Searching Help Printing Help File Topics ...
Страница 17: ...How to Use this Help File To use this help file refer to the following flow chart and the appropriate topics ...
Страница 21: ...Serial Hardware Overview PCI Kits PXI Kits USB Kits ENET Kits ExpressCard Kits PCMCIA Kits ...
Страница 24: ...PCI 485I RS 485 two port isolated RS 485 four port isolated ...
Страница 27: ...PXI 8423 RS 485 two port isolated RS 485 four port isolated ...
Страница 63: ...Save Pending Changes To save your changes to this item click Save ...
Страница 65: ...Restore Defaults To reset the fields to their default values at any time click the Defaults button ...
Страница 98: ...0 LPVOID l_SerialInterface sizeof l_SerialInterface LPDWORD l_ByteCount NULL ...
Страница 127: ...2 PORT LEDs USB Serial Hardware LEDs ...
Страница 139: ...Connecting the Cables to a Four Port PXI Serial Board ...
Страница 141: ...67 58 50 41 33 24 16 7 TXD 9 RI 9 ...
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Страница 181: ...How many serial ports can I have on my machine You can have up to 256 serial ports ...
Страница 189: ...nslookup hostname If you still cannot communicate with your device contact National Instruments ...
Страница 201: ...Glossary Prefixes Symbols A B C D E F G H I K L M P R S T U V ...
Страница 203: ...Symbols degrees ohms percent ...
Страница 204: ...A A amperes ANSI American National Standards Institute ...
Страница 205: ...B b bits B bytes baud bits per second bps bits per second ...
Страница 206: ...C C Celsius COM Computer Output Microform used in reference to a communication port CTS clear to send ...
Страница 208: ...E EIA Electronic Industries Association EMI electromagnetic interference ENET Ethernet ...
Страница 209: ...F FCC Federal Communications Commission FIFO First In First Out ft feet ...
Страница 210: ...G G ground ...
Страница 211: ...H HSI handshake input HSO handshake output Hz Hertz ...
Страница 213: ...K Kbaud kilobits per second ...
Страница 214: ...L LED light emitting diode ...
Страница 215: ...M m meters MB megabyte ...
Страница 216: ...P PC personal computer PCI Peripheral Components Interconnect ...
Страница 218: ...S s seconds SCSI Small Computer Systems Interface ...
Страница 220: ...U UART Universal Asynchronous Receiver Transmitter ...
Страница 221: ...V V volts VDC volts direct current VXI VME eXtensions for Instrumentation ...
Страница 222: ...Important Information Warranty Copyright Trademarks Patents Warning Regarding Use of NI Products Compliance ...