3.1.1 CONFIGURATION SWITCH SET “S1”
The DIP switches on S1 set data rate, clock source, async./sync.
mode and carrier control method. The default settings are summarized
in the table below. Following the table is a description of all possible S-
1 switch settings.
S1-1 through S1-4: Data Rate Setting
Switches S1-1 through S1-4 are set in combination to determine
the asynchronous and synchronous data rate for the Model 1140ARC.
S1-1
S1-2
S1-3
S1-4
Setting
On
On
On
On
1.2 Kbps
Off
On
On
On
1.8 Kbps
On
Off
On
On
2.4 Kbps
Off
Off
On
On
3.6 Kbps
On
On
Off
On
4.8 Kbps
Off
On
Off
On
7.2 Kbps
On
Off
Off
On
9.6 Kbps
Off
Off
Off
On
14.4 Kbps
On
On
On
Off
19.2 Kbps
Off
On
On
Off
28.8 Kbps
On
On
Off
Off
38.4 Kbps
Off
On
Off
Off
57.6 Kbps
5
S1 SUMMARY TABLE
Position
Function
Factory Default
S1-1
Data Rate
On
S1-2
Data Rate
Off
S1-3
Data Rate
Off
S1-4
Data Rate
On
S1-5
Clock Source
On
S1-6
Clock Source
On
S1-7
Async./Sync.
On
Async.
S1-8
Carrier Control
Off
Constantly On
9,600 bps
Internal
}
}
S1-5 and S1-6: Clock Source
Switches S1-5 and S1-6 are set in combination to determine the
transmit clock source for the Model 1140ARC.
S1-5
S1-6
Setting
On
On
Internal transmit clock
Off
On
Receive recover clock
On
Off
External transmit clock
S1-7: Asynchronous/Synchronous Mode
The setting for switch S1-7 determines whether the Model
1140ARC is in asynchronous or synchronous operating mode.
S1-7
Setting
On
Asynchronous
Off
Synchronous
S1-8: Carrier Control Method
The setting for switch S1-8 determines whether the carrier is
“constantly on” or “controlled by RTS”. This setting allows for operation
in switched carrier, multipoint and/or hardware handshaking
applications.
S1-8
Setting
Off
Constantly On
On
Switched Carrier
6
