5
6
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 1140A.
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
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 1140A.
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 1140A
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 “con-
stantly 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
3.3 CONFIGURATION SWITCH SET “S2”
The DIP switches on S2 set word length, extended signaling rate,
RTS/CTS delay and V.52 and V.54 diagnostic test.
S2-1 and S2-2: Word Length
Switches S2-1 and S2-2 are set in combination to determine the
word length for asynchronous data, including start and stop bits.
S2-1
S2-2
Setting
Off
On
8 bits
On
On
9 bits
Off
Off
10 bits
On
Off
11 bits
S2 SUMMARY TABLE
Position
Function
Factory Default
S2-1
Word Length
Off
S2-2
Word Length
Off
S2-3
Extended Signaling Rate
Off-2.5% to +2.3%
S2-4
RTS/CTS Delay
On
S2-5
RTS/CTS Delay
On
S2-6
Future Use
-
S2-7
Future Use
-
S2-8
V.52/V.54 Tests
Off
Enable
Figure 4. Summary of DIP switch default settings for S2
}
}
7 mS
10 bits
