7
S1-2 and S1-3 CLOCK MODES
Set switch S1-2 and S1-3 to determine the 2701RC’s transmitter
timing.
Network Clock
Transmitter timing is derived using the received line
signal (received recovered) from the network.
Internal Clock
Transmitter timing is derived from an internal clock
source.
External Clock
Transmitter timing is derived from DTE terminal tim
ing.
SWITCH S1-4 THROUGH S1-8: DTE DATA RATE
Use switches S1-4 through S1-8 to set the DTE data rate.
S1-4
S1-5 S1-6
S1-7 S1-8
Speed
ON
OFF
OFF
OFF OFF
64kbps
OFF
ON
OFF
OFF OFF
128kbps
ON
ON
OFF
OFF OFF
192kbps
OFF
OFF
ON
OFF OFF
256kbps
ON
OFF
ON
OFF OFF
320kbps
OFF
ON
ON
OFF OFF
384kbps
ON
ON
ON
OFF OFF
448kbps
OFF
OFF
OFF
ON OFF
512kbps
ON
OFF
OFF
ON OFF
576kbps
OFF
ON
OFF
ON OFF
640kbps
ON
ON
OFF
ON OFF
704kbps
OFF
OFF
ON
ON OFF
768kbps
ON
OFF
ON
ON OFF
832kbps
OFF
ON
ON
ON OFF
896kbps
ON
ON
ON
ON OFF
960kbps
OFF
OFF
OFF
OFF ON
1024kbps
ON
OFF
OFF
OFF ON
1088kbps
OFF
ON
OFF
OFF ON
1152kbps
ON
ON
OFF
OFF ON
1216kbps
OFF
OFF
ON
OFF ON
1280kbps
ON
OFF
ON
OFF ON
1344kbps
OFF
ON
ON
OFF ON
1408kbps
ON
ON
ON
OFF ON
1472kbps
OFF
OFF
OFF
ON ON
1536kbps
ON
OFF
OFF
ON ON
1600kbps
OFF
ON
OFF
ON ON
1664kbps
ON
ON
OFF
ON ON
1728kbps
OFF
OFF
ON
ON ON
1792kbps
ON
OFF
ON
ON ON
1856kbps
OFF
ON
ON
ON ON
1920kbps
ON
ON
ON
ON ON
1984kbps
OFF
OFF
OFF
OFF OFF
Clear Channel 2048kbps
NOTE: When the data rate is set to 2.048Mb/s, the unit is forced
into G.703 mode, and it transmits user data on all 32 time-lots.
There is no framing information; therefore, the CRC4 MF (S2-2)
switch is ignored. In all other rate settings, the unit employs G.704
framing; TS0 is reserved for signaling.
SWITCH S2-1: CAS MULTIFRAME
CAS multiframe uses Timeslot 16 (TS16) to send multiframe (MF)
alignment data. In CAS MF, a MF is defined as 16 frames, where a
frame consists of 32 64kb/s timeslots, numbered 0 to 31. TS16 of the
first frame in the MF contains the CAS MF alignment word in the upper
four bits. The alignment word is always 0000 (binary). The 2701RC
does not perform any signaling in TS16 other than to insert the MF
alignment word, in order to maintain MF alignment. When CAS MF dis-
abled, the unit transmits user data in TS16; therefore, up to 31 chan-
nels are available for user data. When it is enabled, TS16 is not avail-
able to the user. In this case, the user can use up to 30 channels for
data. CAS MF can be used with CRC-4 MF or by itself. When enabled,
both units must employ CAS MF; if one unit is set for CAS MF, and the
other is not, the one using CAS MF will detect a loss of sync.
S1-2 S1-3
Clock Mode
On
On
Network (Recieved Recovered)
Off
On
Internal
On
Off
External
Off
Off
Network (Recieved Recovered)
SWITCH SET 2 SUMMARY TABLE
Position Function Factory Default Selected Option
S2-1
CAS MF
OFF
Disabled
S2-2
CRC-4 multiframe
OFF
Disabled
S2-3
RDL Type
OFF
V.54
S2-4
RDL Response
ON
Enabled
S2-5
TM from DTE
ON
Enabled
S2-6
Front Panel Switch
ON
Enabled
S2-7
NMS/VT-100 Switch
OFF
VT-100
S2-8
Line build out
ON
120 Ohms
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