Comtech EF Data CDM-600/600L - Manual (Page 175)

CDM-600/600L Open Network Satellite Modem Revision 3
Open Network Operations MN/CDM600L.IOM
12–3
12.3 Drop and Insert
Primary Data Rates Supported
G.703, RS-422, V.35, and Serial
LVDS 1544 kbps SD, RD, DDO, IDI
2048 kbps SD, RD, DDO, IDI
Satellite Data Rates Supported
(all have 16/15 overhead)
N x 64 kbps
N = 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, or 24 (T1)
N = 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, or 30 (E1-CCS)
N = 1, 2, 4, 6, 8, 12, 16, 24, 30 (E1-CAS)
Terrestrial Framing Supported G.732/G.733, G.704
Satellite Overhead Rate
16/15 of data rate per IESS-308 Rev. 6 and IESS-309 Rev. 3, or
higher
Timeslot Selection Range
1 to 24 (all T1 modes)
1 to 30 (E1-CAS and E1-CCS)
Arbitrary order, non-contiguous available
Plesiochronous Buffer Sizes
Selectable size of 64 to 262,144 bits, in 16-bit steps (with added
limitations for G.704 frame boundaries)
Buffer Clock Reference
Derived from Insert-Data-In (Insert Clock)
External, Rx (satellite) or Tx (Terrestrial)
Asynchronous Engineering Service Channel
ESC Data Interface Type RS-232, Asynchronous
ESC Data Rate 1/2000 of primary data rate
ESC Data Circuits Supported SD, RD, DSR
Synchronous Engineering Service Channel
ESC Data Interface Type RS-232, synchronous to primary data
ESC Data Rate 1/480 of primary data rate
ESC Data Circuits Supported SD, ST, RD, RT, DSR
High Rate Engineering Service Channel (Future Upgrade)
ESC Data Interface Type Async – configurable async character format
ESC Data Rate Example: 2400 baud at 64 kbps
Faults and Alarms
Satellite Backward Alarm 1 (per IESS-309)
Receive BWA Output Enabled onto terrestrial secondary alarm
12.3.1 D&I Primary Data Interfaces
When configured for D&I operation, multiplexing/demultiplexing follows the IBS satellite frame
structure and ESC features, but with the following changes:
• Accepts and outputs primary data through the G.703 connectors.
• The data rate must be at T1 or E1 rates only. This includes additional links for Drop Data
Out and Insert Data In.
• Clock recovery, dejitter, and encoding/decoding are performed as before.
12.3.2 D&I Framing
The IBS satellite framing/deframing is applied only to selected time slots of the data’s G.704
terrestrial structure.