SWITCH SET S1
The configuration switches on S1 set clock source, RTS/CTS
delay, carrier control, loopback tests. The default settings are
summarized in Figure 3 (above).
S1-1 and S1-2: Clock Source
Switches S1-1 and S1-2 are set in combination to determine the
source of timing for the Model 1090.
S1-1
S1-2
Setting
On
On
Internal
On
Off
Receive recover
Off
On
External transmit clock
Off
Off
Not a valid setting
NOTE: When an X.21 QuickConnect™ module is installed in
one or both base units, one base unit must be configured for
receive recover clock source. The particular application will
dictate which unit must be configured for receive recover clock
source.
5
S1-3: RTS/CTS Delay
Switch S1-3 determines the amount of delay between the time RTS
is activated and the 1090 activates the CTS.
S1-3
Function
On
Short delay (4-9 msec)
Off
Long delay (33-71 msec)
S1-4: LDL Control
Switch S1-4 determines whether the front panel switch can activate
a Local Digital Loopback (LDL) diagnostic test.
S1-4
Function
On
LDL Control Enabled
Off
LDL Control Disabled
S1-5: Carrier Control
The setting for switch S1-5 determines whether the carrier is
“constantly on” or “controlled by RTS”. This setting allows for operation
in switched carrier or hardware handshaking applications.
S1-5
Setting
On
Controlled by RTS
Off
Constantly ON
S1-6: DTE Control of RDL
The setting for switch S1-6 determines whether DTE control of
remote-digital loopback test is enabled or disabled. If DTE control is
disabled, the RDL test can only be initiated by the front panel switch.
S1-6
Setting
On
DTE control enabled
Off
DTE control disabled
S1-7: DTE Control of LAL
The setting for switch S1-7 determines whether DTE control of
local analog loopback test is enabled or disabled. If DTE control is
disabled, the LAL test can only be initiated by the front panel switch.
S1-7
Setting
On
DTE control enabled
Off
DTE control disabled
6
S1 SUMMARY TABLE
Position
Function
Factory Default
S1-1
Clock Source*
On
S1-2
Clock Source*
On
S1-3
RTS/CTS Delay
On
Short Delay
S1-4
LDL Control
Off
Disabled
S1-5
Carrier Control
Off
Constant
S1-6
DTE Control of RDL
Off
Disabled
S1-7
DTE Control of LAL
Off
Disabled
S1-8
V.54 Enable/Disable
Off
Enabled
*See Note in SWITCH SET S1 (Below) for X.21 Clock Sources
Figure 3. Summary of DIP Switch Default Settings for S1
}
Internal
