User's Manual

Installation
Issue 1 November 1998 21
Figure 9. Converter Box in Middle of Transmission
For the most stable transmission, use daisy-chain connections
when you connect multiple wallboards to the converter box. Make
sure each wallboard is connected to its own modular network
adapter.
NOTE:
Do NOT use a star connection. In other words, do not connect
more than two RS-485 cables directly to the terminal block or
to a modular network adapter.
Also note that you CANNOT use a home run connection.
Serial port of
device containing
Wallboards
EOL
Modular
RS-485
Converter
RS-232 Cable
A DB25-to-DB9
Box
EOL Terminator
Modular
Adapter may be
Wallboard
Terminator
with 4-wire
Adapters
Network
data cables
Cable
Network
application software
required
Adapters
with
4-wire
data
cables
Set the terminal switch on the converter box to unterminated .
Attach EOL terminators to the wallboards on each end of the RS-485 transmission line.
Attach two RS-485 cables directly to the terminal block on the converter box.