Installation
Installation
2 - 5
NOTE:
The DB9 console port parameters are 9600 baud, 8 data bits character
size, no parity, and one stop bit.
5.
Set the eight DIP switches on the bottom of the unit to correspond
with your network. Choose one option from each of the following
functional groupings, and be sure not to mix two-wire and four-
wire mode settings. (See Figure 2-4 on page 2-3 for DIP switch
locations.)
NOTE:
Any DIP switch configuration not described here could render your MSS
inoperable. Be sure to follow these instructions carefully.
A. Switches 1 through 3 control wire mode. For more information
on wire modes, see
RS-485 Networking Overview
on page 1-2.
For two-wire mode, set switches 1 through 3 to the
On
position. For four-wire mode, set switches 1 through 3 to the
Off
position.
B. Switches 4 and 5 control termination. RS-485 networks should
only be terminated at the extreme ends.
For termination in two-wire mode, set switch 4 to the
On
position and switch 5 to the
Off
position. For termination in
four-wire mode, set both switches to the
On
position. To
disable termination, set both switches to the
Off
position.
C. Switches 6 and 7 control RX (receive) biasing. Biasing makes
sure that there is a valid idle signal when no units are
transmitting, but may not be needed on your network.
To enable biasing, set both switches to the
On
position. To
disable biasing, set both switches to the
Off
position.
NOTE:
The MSS biasing value is 470 ohms in series with a 0.01 uF capacitor.
D. Switch 8 controls grounding of the shielding. RS-485 serial
cabling should generally have one device providing ground.
For a grounded shield, set switch 8 to the
On
position. For a
floating shield (no ground), set switch 8 to the
Off
position.