Black Box IC107A-R3 - Manual (Page 8)

7
CHAPTER 2: Introduction
2. Introduction
The RS-232
↔RS-422/485 Converter (Data Only) allows your RS-232 and
RS-422/485 equipment to communicate with each other. It operates in full-duplex
mode over 4-wire lines.
A four-wire terminal block on the RS-422/485 port makes installation easy. And
this interface converter is flexible: it can work in either point-to-point or multipoint
applications. You can set the RS-232 interface as either Data Terminal Equipment
(DTE) or Data Communications Equipment (DCE) for a wide range of
applications. The Converter is available either as a standalone device (product
code IC107A-R3 for 115-VAC power or IC107AE-R3 for 230-VAC power) or as a
card (product code IC107C-R3) that can be mounted in an RM005 card-cage rack.
Figures 2-1 and 2-2 illustrate typical Converter applications. In Figure 2-1, the
Converter is labeled “terminated”; this indicates that the Converter’s termination
switch S2 has been set to ON. Also note that although Figure 2-2 shows only two
interconnected Converters, up to 64 of them can be daisychained in a multipoint
system. Both figures show the signal flow for the Converter in full-duplex operation
for both point-to-point and multipoint applications. (Direction of signal flow is
indicated by arrows.)
Figure 2-1. 4-wire full-duplex point-to-point application.
Figure 2-2. 4-wire full-duplex multipoint application.
R x B
T x A
T x A
R x A
RS-232
Device
RS-422/485
Device T x B
T x B
R x B
R x A
Terminated
RS-232 <—> RS-422/485
Interface Converter