20
RS-232 TO RS-485 INTERFACE CONVERTER W/OPTO ISOLATION
4.1.4 2-W
IRE
C
ONNECTION
U
SING
T
ERMINAL
B
LOCKS
Most RS-485 devices employ a two-wire, half-duplex
configuration. When using this configuration, be sure
to first set the IC525A-F or IC525A-M to half-duplex
mode by switching DIP switches and jumpers (refer to
Chapter 3
for this configuration)—then use only the
transmit (XMT) pair, as shown below.
Converter Signal
RS-485 Signal
XMT+ - - - - - - - - - - - - - - - - - - +
XMT- - - - - - - - - - - - - - - - - - - -
4.2 Daisychain Topology
The Converter supports multipoint applications using a
daisychain topology.
Using a daisychain topology, you can connect several
Converters together in a master/slave arrangement.
Maximum distance between the units will vary based
upon the number of drops, data rate, wire gauge, etc.
Figure 4-6
shows how to wire the two-pair cables
properly for a Converter daisychain topology.
