Serial Communication Converters & Adapters
Instruction Manual
14
ACC1003 USB RS-485
Converter
Description
The ACC1003 converts USB to balanced, full or half-
duplex RS-422 or RS-485 signals.
The ACC1003 has a removable screw terminal
connector for the RS-485 terminals which includes
Transmit Data (DO) and (/DO), Receive Data (DI) and
(/DI), and Signal Ground.
Baud rates are automatic and handled by the
ACC1003.
The ACC1003 has three diagnostic LEDs: a Power (P)
LED to show when the converter is powered properly, a
Transmit Data (TX) LED to show when the converter is
sending data out from the PC side, and a Receive Data
(RX) LED to show when the converter is receiving data
from the network side.
The DIP switch SW1 is located inside the case and
allows for system configurations.
Installation
The DIP switch SW1 allows for several different
options. Factory settings for the switch are shown in
Figure 25. ACC1003 DIP Switch Location
The termination switch position adds an internal
120 ohm termination resistor when ON (up).
Termination should be used on both ends of the
network with high data rates and long wiring runs.
To configure a two-wire network set both of the 2-wire
switch positions to ON (up). For a four-wire network set
both of the 2-wire switches to OFF (down).
When the RS-422 switch position is ON (up) and the
RS-485 switch position is OFF (down) it is configured
for an RS-422 network. When the RS-422 switch
position is OFF (down) and the RS-485 switch position
is ON (up) it is configured for an RS-485 network.
ACC1003 DIP Switch Settings
SW1 Switch
Position
ON Setting Function
1
Network Termination
Included (120 ohm)
2
2-Wire Network Mode
Connection (factory setting)
3
2-Wire Network Mode
Connection (factory setting)
4
RS-422 Mode
5
RS-485 Mode (factory
setting)
Figure 26. ACC1003 DIP Switch Settings
1 2 3 4 5
ON
Switch in
ON/UP
Position