B&B Electronics 485DRCI-PH Quick Start Manual

Product Overview

DB9 Terminal
Power Data
Port Block
LED LEDs
Ground DIP 10 to 48 VDC
lug Switches 1.9 W Max
Grounding the unit is recommended
Connect a grounding wire from the
ground lug
Set DIP Switches
1
Communications Mode
Switch
1 2
RS-485 2-Wire
ON ON
Half Duplex
RS-485 4-Wire
ON OFF
Full Duplex
OFF OFF
RS-422 Full Duplex
Built-In Termination Resistor
Use built-in 120Ω Termination
Use External or No Termination
Built-In Transmit Bias Resistor
Data
LEDs
Use External or No Bias Resistor
Use built-in 1.2K Ω Transmit Bias Resistor
Built-In Receive Bias Resistor
Use External or No Bias Resistor
Use built-in 1.2K Ω Receive Bias Resistor
SWITCH POSITION 8 IS NOT USED
For an explanation of RS-485 termination and
biasing requirements, refer to B&B Electronics'
RS-485 application note. This publication can
be downloaded at: www.bb-elec.com
3 4 2
ON ON
OFF OFF
Terminal
OFF OFF
A
B
Switch
C
5
D
ON
OFF
E
Switch
6
ON
OFF
Switch
7
ON
OFF
DB9 Pinout
Wire the Converter
RS-422/485
RS-485 2-Wire
4-Wire
*** TDA (-)
*** TDB (+)
Data A (-) RDA (-)
Data B (+) RDB (+)
GND GND
DIP Switch RS-422/485 4-Wire
1 2 3 4 5
OFF OFF OFF ***
On/Off
Position 1 = ON for RS-485, OFF for RS-422
Positions 5,6,7 are used for termination and biasing
DIP Switch RS-485 2-Wire
1 2 3 4 5
ON ON ON ON x
Positions 5,6,7 are used for termination and biasing
Loopback Test
3
C
onfigure for RS-485 Four wire. Jumper terminals A to C and
B to D. Connect a PC to the RS-232 port (see Step 3). Using
HyperTerminal or similar program, connect to the appropriate
COM port. Turn off HyperTerminal local Echo. Transmit data.
The same data should be returned. When data is sent and
looped back, the TD and RD LED's will blink on both ports.
Check LEDs
4
LEDs
Power Red. ON when power is
LED applied
Data Green, LEDs flash when data
LEDs is present on the port
6 7
*** ***
6 7
x x