Serial Instrument Control
Interfaces for USB
NI USB-232 Series, NI USB-485 Series
• Compatible with standard PC
serial port
• 1, 2, and 4-port versions
• Handle RTS/CTS hardware
handshake lines
• 128 B transmit and receive FIFOs
• 5,6,7, or 8 data bits
New
NI USB-232
• RS-232 interface
• 230.4 kb/s maximum transfer rate
• Software-selectable DTE or DCE
transceiver modes (2 and 4-port
models only)
Operating Systems
Windows 2000/XP
NI USB-485
• RS-485 or RS-422 interface
• 460.8 kb/s maximum transfer rate
• Communicates with up to
31 devices
• Automatic transceiver-control
mode for 2-wire RS-485 devices
• Software-selectable biasing
• Cable lengths up to 1.2 km
(4,000 ft)
Recommended Software
• LabVIEW
™
• LabWindows
™
/CVI
™
• Measurement Studio
™
Other Compatible Software
• C/C++
• Visual Basic
• Any package with the
Microsoft serial driver interface
Driver Software (included)
• NI-Serial
Overview
The National Instruments USB-232 and USB-485 transform your
Universal Serial Bus (USB) port into asynchronous serial ports for
communication with serial devices. The NI USB-232 and USB-485
are available in either 1, 2, or 4-port versions and use standard
RS-232, RS-422, or RS-485 communications. All products include
driver software for Windows 2000/XP. You can install and use the
USB-232 and USB-485 as standard serial ports from your existing
applications or with applications written with NI-VISA.
Additionally, the USB-232 2 and 4-port
versions feature software-selectable
DTE or DCE transceiver modes, as well
as an automatic transceiver detection
mode, or Auto232. The USB-485
features software selectable biasing;
therefore, you can turn biasing on and
off for each port through software.
INFO CODES
For more information
or to order products
online, visit
ni.com/info
and enter:
usb232
usb485
BUY ONLINE!
Specifications
FIFO size .................................................
Maximum transfer rate............................
USB connector (1 port) ............................
USB connector (2 and 4 port) ..................
Serial connectors......................................
Noise emissions .......................................
128 B
460.8 kb/s (RS-485); 230.4 kb/s (RS-232)
captive cable with USB series A plug
USB standard series B connector
DB-9
Class A
Development environments, such as
Visual Basic, Visual C++, and Excel, as
well as National Instruments LabVIEW, LabWindows/CVI and
Measurement Studio, can access the serial ports using standard
serial I/O functions.
Power Requirements
5 VDC (from USB) ........................................ USB-232 (100 mA typ, 200 mA max),
USB-232/2 (200 mA typ, 500 mA max),
USB-232/4 (300 mA typ, 500 mA max),
USB-485 (175 mA typ, 500 mA max)
USB-485/2 (300 mA typ, 500 mA max),
+12 VDC (from supply furnished)............ USB-485/4 (225 mA typ, 500 mA max)
Ordering Information
Model
NI USB-232
NI USB-232/2
NI USB-232/4
NI USB-485
NI USB-485/2
NI USB-485/4
Serial Port
RS-232
RS-232
RS-232
RS-485/RS-422
RS-485/RS-422
RS-485/RS-422
Number
of Ports
1
2
4
1
2
4
Part
Number
778472-01
778473-02
778473-04
778475-01
778476-02
778476-P4*
Operating Environment
Ambient temperature............................... 0 to 70 °C
Relative humidity...................................... 10 to 90%, noncondensing
Storage Environment
Ambient temperature (1 port).................. -40 to 80 °C
Ambient temperature (2 and 4 port)........ -40 to 85 °C
Relative humidity...................................... 10 to 90%, noncondensing
*External 12 VDC power supply included
P = Power Cord Type
0 = U.S. 120 VAC
2 = Swiss 220 VAC
3 = Australian 240 VAC
4 = Universal Euro 240 VAC
5 = North American 240 VAC
6 = United Kingdom 240 VAC
Electrostatic Discharge Protection
Case contact and air discharge................ ±4 kV
RS-232 and RS-435 data lines ................. ±15 kV (HBM)
NI [ NATIONAL INSTRUMENTS CORPORATION ]
