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CHAPTER 2: Introduction
2.1 General
The RS-232 to Fiber Optic Multiplexor is available in two major model types:
one with 8 channels (product codes beginning with “MX035”), and one with
16 channels (product codes beginning with “MX036”). Both models are built
from the same circuit board and are identical in every way except for the
number of channels. An 8-channel unit can communicate with channels 1
through 8 of the 16-channel unit if the two units are connected together.
There are two other points of difference in this product line. First, product
codes in which the letter “A” follows “MX035” or “MX036” use 120 VAC;
codes with the letters “AE” in this position use 240 VAC. Second, codes that
end with the “A” or “AE” have SMA 905 fiberoptic connectors; codes in which
“-ST” follows the “A” or “AE” have ST
®
connectors.
Using rear-panel switches, you can independently configure each full-
duplex RS-232 channel of either multiplexor in a pair of these muxes for one
of five modes of operation, three asynchronous and two synchronous. The
multiplexor is transparent to data rates up to 19,200 bps in the asynchronous
modes, and is transparent to sub-protocols and data formats in both the
asynchronous and synchronous modes.
1. The first mode of operation is single-channel asynchronous: The
multiplexor transmits one data signal, one DTR/CTS-handshaking control,
and no other signals.
2. The second mode is only slightly different: In addition to the DTR/
CTS handshaking, a second, auxiliary (control or data) signal is present.
3. The third mode is triple-channel asynchronous: The multiplexor sends
three separate data signals on each channel, across a 3-to-1 adapter cable (our
product code EYN355), without any handshaking or control signals. This
allows you to connect three asynchronous RS-232 “dumb terminals” to each of
the mux’s ports; in this mode, 8-channel units can handle 24 async data-only
channels and 16-channel units can handle 48 async data-only channels.
4. The fourth mode is synchronous with internal clocking (the multiplexor
supplies the clock to the terminal device). This mode supports transmission
of one handshaking signal, which allows the Data Terminal Ready (DTR)
input at one end of the system to control the Clear to Send (CTS) output at
the other end. Data rates of 1200, 2400, 4800, 9600, and 19,200 bps are
available.
2. Introduction
