5
6
3.0 CONFIGURATION
This section describes the location and orientation of the Model
2085RC's configuration switches, provides detailed instructions on set-
ting each switch and describes the settings for each of the rear con-
nection cards.
3.1 FRONT CARD CONFIGURATION
The Model 2085RC front card houses interface converters –-
Converter “A” and Converter “B”–
each using two sets of DIP switches.
The locations of these switches are shown in Figure 1 (below). These
switches are accessible when the card is slid out of the rack chassis.
Once configured, the Model 2085RC is designed to operate transpar-
ently, without need for frequent re-configuration.
Each of the DIP switches on the Model 2085RC function card is a
4-position switch. Figure 2 (below) shows the On/Off orientation of
these switches. Use a small screw driver or similar instrument to set
each individual switch.
3.1.1 SWITCH SETTINGS - CONVERTER “A”
DIP switches S1 and S2 configure converter A on the Model
2085RC front card. The tables below provide an overview of converter
A switch settings, including factory default settings. Following the
tables is a descriptions of each switch’s function.
SWITCH SET “S1”
DIP switch S1 is used to configure receive impedance,
RTS/CTS delay, carrier control operation and “echo” enable/disable.
The summary table below shows the factory default settings for switch
S1. Following the summary table is a detailed description of each indi-
vidual switch.
S1-1: Receive Impedance
The setting for switch S1-1 selects the impedance of the input
receiver. You may select either a “low” impedance of 120 Ohms or a
“high” impedance of 16K Ohms. By selecting the proper impedance for
each drop, there may be up to 50 receivers in one application.
S1-1
Setting
On
Low (120 Ohm)
Off
High (16K Ohm typical)
S1-2: RTS/CTS Delay
The setting for switch S1-2 determines the amount of delay
between the time the Model 2085RC “sees” RTS and when it sends
CTS. Note: RTS/CTS Delay setting should be based upon transmis-
sion timing.
S1-2
Setting
On
8 msec
Off
no delay
Figure 1. Model 2085RC board, showing location of configuration switches.
“ON”
“OFF”
Figure 2. Close-up of DIP switches, showing ON/OFF orientation.
1
2
3
4
ON
S2
S1
S3
S4
SWITCH S1 SUMMARY TABLE (factory defaults in bold)
Position
Function
ON Position
OFF Position
S1-1
RX Impedance
120 Ohm
16K Ohm
S1-2
RTS/CTS Delay
8 msec
No Delay
S1-3
Carrier Control
RTS Controlled
Constantly On
S1-4
Echo Mode
Echo ON
Echo OFF
