The
CVT-485-1 is a compact, rugged, industrial-grade, port-powered, bi-directional RS232 to RS485 converter, which can be used to convert any standard unbalanced RS-232C port into a two-wire half-duplex balanced RS485 port and vice versa.
This industrial-grade RS232 to RS485 converter operates within a wide temperature range (-40F to 185F / -40C to 85C), features 600W surge protection and 15kV static protection, and comes with a built-in 120 Ohm terminator for system reliability and easy installation. The unit is powered from the RS232 data line; it also supports data direction auto-turnaround, which automatically enables the RS485 transceiver when data is present on the RS232 side. Therefore, it requires no external power, software drivers or flow control, making the unit a rugged, highly reliable, and truly plug-and-play device.
Declaration of Conformity |
RS232 to RS485 Converter data sheet
FEATURES (INDUSTRIAL RS232 TO RS485 CONVERTER)
- Converts RS232 to 2-wire RS485 and vice versa.
- 300 to 115.2K Baud operation (auto-sensing & self-adjusting).
- Industrial grade with wide temperature range (-40F to 185F / -40C to 85C),
surge (600W) and static protection (15kV).
- Port-powered, no external power or RTS, DTR required.
- Accepts external 5VDC regulated power if the port-power is insufficient.
- Plug and play (hot-pluggable, data format auto-sensing & self-adjusting).
- Data direction auto-turnaround, no flow control is required.
- Built-in surge protection, static protection and circuit protection.
- Built-in 120Ω end-of-line terminator for system reliability and easy installation.
- Surface Mount Technology manufactured to ISO-9001 standards.
- CE certified: strictly certified by world-class lab TUV.
- 5-year manufacturer's warranty.
120 Ohm End-of-Line Terminator (Built-in)
Self-explanatory, the 120 Ohm end-of-line terminator is to be connected at the end of the RS485/RS422 transmission line. This is important for building a reliable RS485/RS422 system, not only because of impedance matching, but also for the reduction of signal reflections and noise problems.
Note: The 120 Ohm end-of-line terminator adds heavy DC loading to a system and, therefore, it should be connected only when the RS485/RS422's distance is over 660ft (200m).
PRODUCT PHOTOS (INDUSTRIAL RS232 TO RS485 CONVERTER)
SPECIFICATIONS (INDUSTRIAL RS232 TO RS485
CONVERTER)
|
Part Number: |
CVT-485-1 |
|
Compatibility: |
EIA/TIA
RS-232C standard and RS-485 standard |
|
Power Source: |
Port power from RS232 data line |
|
Current Consumption: |
Less than 10mA |
|
Baud
Rates: |
300 to 115,200bps (Auto-sensing &
Self-adjusting) |
|
Distance: |
Depending on power from RS232 port, will
transmit up to 4000ft (1.2km) at 19,200bps |
|
Connector: |
RS232 Side: DB-9 Female; RS485 Side: DB-9
Male; Termination Board: DB-9 Female and a 4-Way Terminal Block |
|
Maximum number of drops: |
128
|
|
End of Line Terminator: |
120Ω (Built-in) |
|
Surge protection: |
600W |
|
Static
protection (ESD): |
Up to 15KV |
|
Dimensions (H x W x D): |
0.63 x 1.3 x 3.4 in (16 x 32 x 86 mm) |
|
Weight: |
1.27 oz (36 g) |
|
Operating Temperature: |
-40F
to 185F (-40C to 85C) |
|
Operating Humidity: |
Up to 90% RH (no condensation) |
CONVERTER CONNECTOR / TERMINAL BLOCK PINOUTS
|
RS232 Side |
|
Pin |
1 |
4 |
6 |
7 |
8 |
2 |
3 |
5 |
|
Signal |
DCD |
DSR |
DTR |
CTS |
RTS |
TX |
RX |
GND |
|
Function |
Tied |
Tied |
TX |
RX |
GND |
|
|
 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. |
|
DB-9 Female (view from front) |
|
|
|
RS485 Side |
|
Pin |
1 |
3 |
5 |
9 |
6 |
7 |
|
Terminal Block |
A+ |
B- |
GND |
+5V |
Jumper
(120) |
|
Function |
RS485+ |
RS485- |
GND |
+5V measurement |
Terminate/remove Jumper 120 to turn ON/OFF the 120Ω
end-of-line terminator. |
|
|
|
|
 Note:
The CVT-485-1 comes with a 4-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.
DB-9 Male (view from front) / Terminal Block
|
120 OHM
END-OF-LINE JUMPER SETTINGS
IMPORTANT: Turn ON Jumper 120 (120
Ohm End-Of-Line Terminator) at both ends of the RS-485 bus.
CONNECTIONS (RS485 BUS, RS232 EXTENSION)
 |
|
|
Figure 1: Master-Slave
Multi-Drop Connections |
|
 |
|
|
Figure 2: Extending
Half-Duplex RS232 Distance (Data Only) |
TROUBLESHOOTING INSTRUCTIONS FOR RS232 TO RS485
CONVERTER
| 1) Port power measurement |
 |
|
| Measure
pin +5V and GND with a voltmeter, and be sure that it is around +5VDC (when RS232 port is connected). |
|
|
| 2) Loopback Test |
 |
|
- Connect two numbers
of CVT-485-1 to your PCs COM ports and connect A+ to A+, B- to B- on the
RS485 terminal blocks (as shown above).
- Run two instances
of the
232Analyzer FREE version software
on your computer.
- Select "ASCII" for
both the Send and Receive data formats. Then send command and/or string
such as "CommFront" from one COM port. You should receive an echo of the
command/string sent ("CommFront") on the other COM port. 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.
|
 |
| Screenshot 1: Send commands
from 1st instance of the 232Analyzer software. |
|
 |
| Screenshot 2: Receive
commands from 2nd instance of the 232Analyzer software. |
|
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.
