Comtech EF Data SDM-300A - Manual (Page 325)

SDM-300A Sattellite Modem Revision 6
Flex Mux MN/SDM300A.IOM
15–5
Table 15-3. Demultiplexer Specific Specifications
Demultiplexer Specific Specifications
Channel # 1 Satellite Data Rates E1 Data Rates (N x 64 kbps)
N = 1 through 6, 8, 10, 12, 15, 16, 20, 24 or 30 (E1_CCS)
N = 1, 2, 4, 6, 8, 12, 16, 24, 30 (E1_CAS)
E1 (2048 kbps)
T1 Data Rates
N = 1 through 6, 8, 10, 12, 15, 16, 20 or 24 (T1)
(add 9 or 18 for T1, using special IBS superframe)
T1 (1544 kbps)
Channel # 1 Terrestrial Framing G.732, G.733 and G.704
Channel # 1 Satellite Overhead 16/15 of data rate per IESS-308, Rev. 6 and IESS-309, Rev. 3.
Applies when only Channel # 1 is selected, all other channels are “disabled”.
Channel # 1 Timeslot Selection 1 to 24 (All T1 modes)
1 to 15, 17 to 31 (E1_CAS and E1_CCS)
1 to 31 (E1_31TS)(Slot 16 available)
Arbitrary order, non-contiguous available.
Channel # 1 Plesiochronous Buffer Sizes 7.5, 15 and 30 ms (E1_CAS)
1, 2, 4, 8, 16 and 32 ms (E1_CCS)
6, 12, 24 and 32 ms (T1_S and T1_ESF_S)
1, 2, 4, 8, 16 and 32 ms (all other modes)
Channel # 1 Buffer Clock Reference Driven from Insert Data In (Insert Clock)
Receive Satellite Clock
External Clock
SCT from Modulator
User Channel # 2 ADPCM Audio Channel 32 kbps audio channel 600 Ω, balanced 4-wire.
Channel # 3 and # 4 Data Interface
(Synchronous mode)
The demultiplexer supports synchronous data for each tributary. The tributary
interfaces use DCE conventions with data (Receive data) and clock (Receive
clock) sourced by the demultiplexer.
Channel # 3 and # 4 Data Interface
(Asynchronous mode)
The demultiplexer supports asynchronous data interface for each tributary. The
tributary data interface used (DCE) conventions with data (Receive data)
sourced by demultiplexer. Asynchronous mode at the demultiplexer is really no
different from synchronous mode, because the multiplex equipment does Async
to sync conversion prior to transmission over the satellite channel. The
asynchronous data is passed in a virtual transparent mode and retains the
same framing and formatting including start/stop and parity as the transmitting
equipment.
Channel # 3 and # 4 Clock Output 50% duty clock ± 10%, clock (Receive Timing) is phase locked to aggregate
clock recovered by the modem.