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CommFront offers
a range of high-quality, industrial-grade, port-powered
RS232 to RS485 / RS422 converters. These plug-and-play
products operate within a
wide temperature range (-40ºF
to 185ºF / -40ºC to 85ºC),
feature 600W surge protection and 15kV static protection, and come with
built-in 120 Ohm terminators for easy installation. Whether
your environment is commercial or industrial, "clean" or "noisy"*, our RS232 to RS485
/ RS422
converter products provide safe, easy, and cost-effective solutions for your
data-conversion
applications.
* A "noisy" environment
is an area
surrounded by ground loops, transient surges
and spikes, which could potentially harm your expensive
equipment such as computers and data communication
devices.
The CommFront opto-isolated converters and isolators provide
simple and effective ways to protect your devices from such
potential harms. |
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RS232 TO RS485 CONVERTER /
RS232 TO RS422 CONVERTER
SELECTION TABLE
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Part
Number |
Description |
Price |
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CVT-422-1 |
RS232 <=> 4-wire RS422
Converter
(Industrial/Port-powered/300 to 115.2K Baud) |
$47.95
Order |
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CVT-485_422-1 |
RS232 <=> 2-wire RS485 or
4-wire RS422 Converter
(Industrial/Port-powered/300 to 115.2K Baud) |
$54.95
Order |
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CVT-422-3 |
RS232 <=> 4-wire RS422
Converter
(Isolated/Industrial/Port-powered/300 to 57.6K Baud) |
$74.95
Order |
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CVT-485_422-3 |
RS232 <=> 2-wire RS485 or
4-wire RS422 Converter
(Isolated/Industrial/Port-powered/300 to 57.6K Baud) |
$79.95
Order |
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INTRODUCTION
(ISOLATED RS232 TO RS485 RS422 CONVERTER) |
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$89.95
Order Here |
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The CVT-485_422-3 is
an
industrial grade (wide temperature range with surge & static
protection) optically isolated bi-directional
RS-232 to RS-485 converter / RS-232 to
RS-422 converter, which can be used to convert any standard
RS-232C port into a two-wire half-duplex RS-485 port or a
four-wire full-duplex RS-422 port and vice versa. This
product features opto-isolation circuitry, which effectively
protect your RS-232 devices from
ground
loops, transient surges and spikes.
The unit is powered from the
RS-232 data line; it also supports data direction
auto-turnaround. Therefore, no external power or flow
control is required.
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data sheet |
FAQs |
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FEATURES (ISOLATED RS232 TO
RS485 RS422 CONVERTER) |
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Converts RS232 to
RS485 or RS422 (with opto-isolation) and vice versa. |
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Industrial
grade with wide temperature range, surge and static protection. |
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Optical isolation effectively protects your RS-232 devices from
ground loops,
transient surges and spikes. |
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Optical isolation eliminates ground loop and noise problems. |
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Plug and play (hot-pluggable, data format auto-sensing &
self-adjusting). |
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Port-powered, no external power or RTS, DTR required. |
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Data direction auto-turnaround, no flow control is required. |
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Built-in
surge
protection, static protection and circuit protection. |
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Built-in 120Ω end-of-line terminator for easy
installation. |
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Surface Mount
Technology manufactured to ISO-9001 standards. |
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CE
certified. |
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5-year
manufacturer's warranty. |
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SPECIFICATIONS (ISOLATED RS232
TO RS485 RS422 CONVERTER) |
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Part Number: |
CVT-485_422-3 |
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Compatibility: |
EIA/TIA
RS-232C standard and RS-485/RS-422 standard |
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Power Source: |
Port power
from RS232 data line |
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Current
Consumption: |
Less than
10mA |
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Optical
Isolation: |
2500Vrms
(AC, 1 min) |
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Baud
Rates: |
300
to 57,600bps (auto-sensing & self-adjusting) |
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Distance: |
RS-232 side:
16 ft (5m); RS-485/RS-422 side: Depending on power from RS232
port, will transmit up to 4000 ft (1.2km) at 19,200bps |
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Connector: |
RS232 Side:
DB-9 Female; RS485/RS422 Side: DB-9 Male; Termination Board:
DB-9 Female and a 6-Way Terminal Block |
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Maximum number
of drops: |
64 |
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End of Line
Terminator: |
120Ω
(Built-in) |
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Surge protection: |
600W |
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Static
protection (ESD): |
Up to 15KV |
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Dimensions (H
x W x D): |
0.63 x 1.3
x 3.5 in (16 x 32 x 90 mm) |
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Weight: |
1.37 oz (39
g) |
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Operating
Temperature: |
-40ºF to
185ºF (-40ºC to 85ºC) |
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Operating
Humidity: |
Up to 90%
RH (no condensation) |
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CONVERTER CONNECTOR / TERMINAL
BLOCK PINOUTS |
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RS232 Side |
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Pin |
1 |
4 |
6 |
7 |
8 |
2 |
3 |
5 |
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Signal |
DCD |
DSR |
DTR |
CTS |
RTS |
TX |
RX |
GND |
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Function |
Tied |
Tied |
TX |
RX |
GND |
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 Note:
Some software requires handshake line
acknowledgements. To satisfy the requirements, our
converter's handshake lines are tied together (DCD,
DTR, and DSR tied together, and RTS and CTS tied
together). Therefore, you don't have to modify your
existing software. |
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DB-9
Female (view from front) |
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RS485 / RS422 Side |
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Pin |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
4 |
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Jumper |
J2
(default: ON) |
J3
(default: ON) |
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J1
(default: ON) |
J4
(default: ON) |
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RS485 |
A+ (J2 ON) |
B- (J3 ON) |
GND |
(J1 ON) |
Terminate/remove Jumper J4
to turn ON/OFF the 120Ω
end-of-line terminator. |
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RS422 |
(J2 OFF) |
(J3 OFF) |
GND |
(J1 OFF) |
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TX+ |
RX+ |
TX- |
RX- |
GND |
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 Note:
The CVT-485_422-3 comes with a 6-way terminal block for easy
wire connections. However, you may choose not to use the
terminal block provided and simply follow the above table
for pin assignments. |
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DB-9 Male (view from front) /
Terminal Block |
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JUMPER SETTINGS FOR RS485 /
RS422 MODES AND 120 OHM END-OF-LINE TERMINATOR |
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1) RS232 to RS485 Mode |
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- Turn ON Jumper 1, 2 & 3 for RS-485 mode;
- IMPORTANT: Turn ON J4 (120 Ohm End-Of-Line
Terminator) at both ends of the RS-485 bus. |
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2) RS232 to RS422 Mode |
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- Turn OFF Jumper 1, 2 & 3 for
RS-422 mode;
- IMPORTANT: Turn ON J4 (120 Ohm End-Of-Line
Terminator) at both ends of the RS-422 (or 4-wire
RS-485) bus. |
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CONNECTIONS (RS485 BUS, RS422
BUS, RS232 DISTANCE EXTENSION) |
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Figure 1: Master-Slave
Multi-Drop Connections (RS485) |
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Figure 2: Master-Slave
Multi-Drop Connections (RS422)
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Figure 3:
Extending Full-Duplex RS-232
Distance with Opto-Isolation |
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TROUBLESHOOT RS232 TO RS485 /
RS422 ISOLATED CONVERTER |
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1) Port power measurement |
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Measure pin
+5V and GND with a voltmeter, and be sure that it is around
+5VDC (when RS232 port is connected). Otherwise, please
check the power on the RS232 port to which the converter is
connected (as shown below). |
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Note: CommFront
port-powered converters require a -7 to -15VDC on the TX
line (Pin 3 on DTE or Pin 2 on DCE) of the RS232 port to
which the converter is connected.
You can connect CVT-485_422-3
to a DTE device which comes with a DB-9 Male connector;
however, if it is a DCE device, you will need to swap Pin 2
and 3 before connecting to the converter. |
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2) Loopback Test |
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Connect a CVT-485_422-3 to your PC's COM port and remove
Jumper 1 and terminate Jumper 2 and 3 on the RS485/422
terminal block (as shown above).
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Run 232Analyzer
FREE version software on your computer.
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Select "ASCII" for both the Send and Receive data
formats. Then send command and/or string such as
"CommFront" from the 232Analyzer software. You should
receive an echo of the command/string sent
("CommFront"). By performing a simple loopback test like
this, you can test both the transmitter and receiver of
the converter. This is very helpful when you are in
doubt about the performance of your converter.
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Screenshot: Send/receive
commands from 232Analyzer software. |
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232Analyzer is an advanced RS232 Serial Protocol Analyzer
software
that allows you to control, monitor and analyze serial port
(RS232 / RS485 / RS422 / TTL, etc.) activities.
Not just the data,
it also allows you to monitor or change RS-232's line
states: RTS, CTS, DTR, DSR, DCD, and RI.
The FREE version (no time
limitation) can be downloaded from
here.
TECH NOTES
RS-232: 3 easy steps to understand and control your RS232
devices |
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