Far-End Loop/Normal; Ext Clock/Int Clock; Adaptive/Normal; Assert Dtr/Normal - Northern Telecom DMS-100 Series Installation And Maintenance Manual

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Far-end Loop/Normal:

0 This switch (number 3 on SW2) selects either normal operation
0 a far-end loopback test.
0 DU is set for normal operation.
0 end Loop and a call is placed to another DU, the integrity of the
0 end-to-end data channel is checked by using test equipment or by
0 entering characters from the DTE.
0 DU tells the far-end DU to loop data back at the RS-232C inter-
0 face. Characters entered on the DTE keyboard are echoed back
0 the DTE. The Under Test LED on both DUs is on during a far-end
0 loop back test.
0 /CH /AV /DF) on page 5-10.
0
T-and-R Loop/Normal:
0 This switch (number 4 on SW2) selects either normal operation or
0 a Tip (T) and Ring (R) loopback on the Tip and Ring leads.
0 this switch is set to Normal, the DU is set for normal operation.
0 When the switch is set to T-and-R Loop, the DU is isolated from
0 the loop and data is looped back
0 toward the DTE.
0 to be placed to another DU.
0 board are echoed back to the DTE.
0 Tests (NT4X25AD /CH /AV /DF) on page 5-10.
0

Ext Clock/Int Clock:

0 When operating at synchronous speeds, this option switch
0 5 on SW2) selects the clock for clocking data from the DTE to the
0 DU. When Ext (external) Clock is selected, the DTE provides the
0 clock. When Int (internal) Clock is selected,
0 the clock. Int Clock is the usual setting.
0 smissions, select
0 communicating DUs.
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Adaptive/Normal:

0 This option switch (number 6 on SW2) allows the DU
0 the operating parameters, such as speed and mode, of the far-end
0 DU. When the switch is set to Adaptive, the DU adapts its
0 ating parameters
0 far-end DU.
0 adapt to the operating parameters of the far-end DU.
0 nect LED flashes until both DUs have compatible operating parame-
0 ters).
0

Assert DTR/Normal:

0 When this switch (number 7 on SW2) is set
0 Terminal Ready), the DU assumes that the RS-232C DTR signal from
0 the DTE is always on.
0 does not require the DTE to control the DTR
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When this switch is set to Normal, the
For more details see
A T-and-R loopback test does not require a call
Characters entered on the
the Int Clock option for at least one of the
(data rate and synch/asynch mode) to match the
When the switch is set to Normal, the
Select the Assert DTR option when the user
When the switch is set
When activated,
Loopback Tests
at the Tip and
For more details see Loopback
the
For synchronous tran-
to Assert
signal.
297-2121-226
VINTAGE 05.01
or
to Far-
the near-end
to
(NT4X25AD
When
Ring leads,
DTE key-
(number
DU provides
to adapt to
oper-
DU does not
(The Con-
DTR (Data
When the
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