10
RS-232 TO FIBER OPTIC MULTIPLEXOR
This chapter describes how to configure each channel for the desired mode
of operation and how to operate the multiplexor.
4.1 Modes of Operation
On each channel of the multiplexor, one of five modes of operation
can be independently selected:
1. Single asynchronous data line with one control signal.
2. Single asynchronous data line with one control and one auxilary signal.
3. Three async data lines on the same port without control signals
(using 3-to-1 adapter cable).
4. Single synchronous data line using internal clock.
5. Single synchronous data line using external clock.
See
Section 4.3
for more detailed information on the supported control
signals and their functions.
Select the operating mode of each channel with the DIP switch located
directly above that channel’s connector. The function of each position in the
switch is indicated by the chart in the upper left-hand corner of the rear panel
(see Figure 4-1 on the next page).
4.1.1 S
INGLE
A
SYNCHRONOUS
D
ATA
L
INE
W
ITH
O
NE
C
ONTROL
S
IGNAL
(M
ODE
1)
In this mode of operation, the asynchronous Transmit Data signal fed into
one multiplexor is transmitted to the Receive Data output of the other
multiplexor, the Data Terminal Ready input (Pin 20) at one end controls the
Clear to Send signal (Pin 5) at the other end, and no other signals are passed.
This minimal communication will suffice for many types of “dumb terminals.”
The mux is transparent to asynchronous data rates on a channel in this mode
up to 19,200 bps. To set a given channel for this mode, set all of that
channel’s DIP-switch positions to OFF.
4. Configuration and Operation
