Product Overview
Connect RS-232 Device
Set RS-422/485 Converter Side
Termination Switch:
Set to OFF (recommended)
Connect Your Power Supply
Loopback Test
Set the Dipswitch Settings
for Baud Rate
1
+
+
+
+
2
4
5
6
3
External Power
Supply
Terminal C:
(Ground/V (–)
Terminal F:
V (+)
Converter uses 0.5 W
• Configure for RS-485 4-wire, 9600 baud.
• Jumper terminals H to L, and G to K.
• Connect a PC to the RS-232 port (see
Step 1).
• Using HyperTerminal or similar program,
connect to the appropriate COM port
(remember to set the baud rate at 9600).
Turn off HyperTerminal local echo.
• Start typing. If you can see the data
you are typing, you have a good loop-
back. If you cannot, contact B+B
SmartWorx technical support.
• LED Indicators: Power is ON when power
is applied. TD flashes when RS-422/485
data is sent. RD flashes when RS-
422/485 data is received.
Set DIP
Switches to:
RS-485
4-Wire
L
K
H
G
1
2
3
4
5
6
7
8
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF
LED Indicators
7
+
Terminal Block
Connectors
A – F
Terminal Block
Connectors
G – M
DB9 F Pins
DIP
Switches
1 – 8
Top View
(RS-232 & Power Side)
Bottom View
(RS-422/485 Side)
Please Note:
Terminal block and DIP switch settings located on product.
Additional RS-422/485 technical notes on are available
on the B+B SmartWorx website.
2 Wire 485
4 Wire 485/422
Your Device
Your Device
485LDRC9
485LDRC9
G
K
DATA
B (+)
DATA
A (-)
GND
H
L
J
M
G
TDB
(+)
TDA
(-)
RDB
(+)
RDA
(-)
GND
K
H
L
J
M
SW-1
SW-2
SW-3
SW-4
RS-485 2-Wire Half-Duplex
ON
ON
ON
ON
RS-485 4-Wire Full-Duplex
ON
OFF
OFF
OFF
RS-422 Full-Duplex
OFF
OFF
OFF
OFF
Computer
Your Device
485LDRC9
Field Device
Your Device
485LDRC9
DTE
DCE
D
TD
RD
A
E
B
F
C
GND
D
TD
RD
GND
A
E
B
F
C
Additional technical notes on RS-232 DTE DCE connections
are available on the B+B SmartWorx website.
• Use a straight-through DB9 to DB9 if you are
connecting to a computer (DTE).
•
Use a cross-over (null modem) DB9 to DB9 if you
are not connecting to a computer. (DCE)
For baud rates not listed above, see the B+B SmartWorx website.
SW-6
SW-7
SW-8
Timeout (MS)
2400
OFF
OFF
ON
4.16
4800
OFF
ON
OFF
2.08
9600
ON
OFF
OFF
1.04
19.2K
ON
ON
ON
0.580
Switch 5
Termination technical notes on are
available on the B+B SmartWorx website.
Use the 120Ω
Built-in Termination
ON
Use External or
No Termination
OFF
Transmit Data (Red)
Flashing - RS-422/485 data is transmitted
Receive Data (Red)
Flashing - RS-422/485 data is received
Power (Red)
On - when power applied
With no devices attached, LEDs should be Off; Power On.
TIPS:
If LEDs are On
before
devices are attached, it may indicate the
Termination Resistor is On.
Using termination, with power ON, but no devices connected, may cause
the Receive LED to turn ON solid. The loading from the termination may
cause the Receiver Bias to go into an indeterminate state.
