S2-4 and S2-5: RTS/CTS Delay
The combined settings for switches S2-4 and S2-5 determine the
amount of delay between the time the Model 1140RC “sees” RTS and
when it sends CTS. Options are no delay, 7 ms and 53 ms.
S2-4
S2-5
Setting
On
On
7 mS
Off
On
53 mS
On
Off
No delay
Off
Off
No delay
S2-8: V.54 Loopback Test Enable
To reset the V.54 circuit, set switch S2-6 to the “ON” position, then
back to the “OFF” position..
S2-8
Setting
Off
V.54 Enable
On
V.54 Disable
3.2 REAR CARD CONFIGURATION
The Model 1140RC is compatible with two dual-fiber interface cards,
one with dual ST connectors and one with dual SMA connectors. Both
cards use an HD-26 female for the RS-232 interface. The single
configuration jumper (JB1) functions identically on both cards. Figure 3
(below) shows the jumper’s location.
3.1.2 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. The default settings
are summarized in the table below. Following the table is a description
of all possible S-2 switch settings.
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.
S2-1
S2-2
Setting
Off
On
8 bits
On
On
9 bits
Off
Off
10 bits
On
Off
11 bits
S2-3: Extended Signaling Rate
The setting for switch S2-3 determines the range of variability the
Model 1140RC “looks for” in asynchronous data rates (i.e., the actual
variance from a given frequency level the Model 1140RC will tolerate).
S2-3
Setting
Off
-2.5% to +1% Basic
On
-2.5% to +2.3% Extended
8
7
Figure 3. Model 1140RC rear card jumper location
JB1
(pin 1 on left)
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
}
}
7 mS
10 bits
