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3.1.2 DIP SWITCH S1 SETTINGS
DIP switch S1 is used to configure receive impedance,
2-wire/4-wire operation and "echo" enable/disable. The summary table
below shows the factory default settings for switch S1. Following the
SWITCH S1 SUMMARY TABLE (factory defaults in bold)
Position
S1-1
S1-2*
S1-3*
S1-4
summary table is a detailed description of each individual switch.
*Note: Switches S1-2 and S1-3 should be switched simultaneously
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 16 kOhms. By selecting the proper impedance for
each drop, there may be up to 50 receivers in one application.
S1-1
On
Off
S1-2 and S1-3: 2-wire/4-wire Modes
Switches S1-2 and S1-3 are set together to determine whether the
Model 2089 is in 2-wire or 4-wire operating mode. Note: 2-wire mode
is half-duplex only.
S1-2
On
Off
S1-4: Echo Mode
The setting for switch S1-4 determines whether the Model 2089
echoes data back to the transmitting device (half-duplex mode only).
S1-4
On
Off
Function
RCV Impedance
2-wire/4-wire
2-wire/4-wire
Echo Mode
Setting
Low (120 Ohm)
High (16 kOhm typical)
S1-3
On
Off
Setting
Echo On
Echo Off
OFF Position
16 kOhm typ.
4-wire
4-wire
Echo OFF
Setting
2-wire mode
4-wire mode
6
ON Position
120 Ohm
2-wire
2-wire
Echo ON
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