17
CHAPTER 4. Installation
4.1.2 2-W
IRE
C
ONNECTION
Most RS-485 devices use a two-wire, half-duplex
configuration. When using this configuration, first set
the Converter to “two-wire” mode—then use
only the
transmit (XMT) pair,
as shown in
Figure 4-2
.
Converter Signal
RS-485 Signal
XMT+ - - - - - - - - - - - - - - - - - - >XMT-A
XMT- - - - - - - - - - - - - - - - - - - >XMT-B
Figure 4-2. Crossover cable wiring.
4.1.3 4-W
IRE
C
ONNECTION
U
SING
T
ERMINAL
B
LOCKS
If you purchased the IC525A-F or IC525A-M, you will
need to open the case to access the terminal blocks.
The following instructions will tell you how to open the
case, connect the bare wires to the terminal blocks, and
fasten the strain-relief collar in place so that the wires
won’t pull loose.
1. If the case is not already open, open it now by
twisting it open with a small plastic screwdriver.
2. Strip the outer insulation from the twisted pairs
about one inch from the end as shown in
Figure
4-3
.
