Mocomtech CRS-300 CDM-625 Modem Connections, 1 RMI/TMI Limitations and Considerations

CRS-300 1:10 Redundancy Switch	Revision 16
Cables and Connections	MN/CRS300.IOM

4.5CDM-625 Modem Connections

If adding a modem to an operating 1:N system, care needs to be taken to not interfere with the existing traffic. The cabling and power-up sequence must be correct to avoid contention in the system from the modem Tx carrier. This sequence is detailed in Chapter 7.4.5 (CONFIG)

ACTIVE MODEMS.

4.5.1 RMI/TMI Limitations and Considerations

With some exceptions, Traffic modems with differing data types can all be supported by the Redundant Modem.

Refer to Table 4-1for the RMI, TMIs, and cables required to set up a properly configured redundant system. As shown, and regardless of driving traffic data type, the CRS-300 1:10 Redundancy Switch uses the CRS-310Redundant Modem Interface (RMI) for all driving traffic configurations.

When using the CDM-625 in a CRS-300 1:10 Redundancy system, TMIs may be mixed within the same CRS-300 with some limitations: while the “P2” (DB-15M) connector on the CRS-310 RMI may be used for Balanced / Unbalanced G.703 or Quad E1 traffic, only one of these two traffic data types can be used within the TMIs. Accordingly, a CRS-300 that uses any combination of the CRS-325, CRS-330, or CRS-340 TMIs for Balanced / Unbalanced G.703 traffic cannot have the CRS-365D TMI (for Quad E1 traffic) installed in the same system.

Refer to Figure 4-10through Figure 4-12for graphic examples of this operational dependency; each figure shows permissible TMI types that can be used for the Traffic Modems.

1.Depending on the traffic data type, the appropriate jumper settings are

provided on the TMI to ensure proper operation for EIA-422 with RTS/CTS,

IMPORTANT DTR/DSR signal using the CRS-316, CRS-320 (obsolete), or CRS-340 TMI; or HSSI with CA/TA signals using the CRS-336 TMI. Refer to Chapter 4. MODEM, TMI, AND SWITCH CONFIGURATION in this manual for this important configuration information.

2.When using the CDM-625 in Dedicated Management Port mode, all four of the offline modem’s Ethernet ports will be disabled unless the user configures one of the four ports as the ‘Dedicated Management Port.’ For more information, refer to Sect. 5.4.13.3 CONFIG: IP Æ Setup in the CDM-625 Advanced Satellite Modem Installation and Operation Manual.

4.5.2Carrier-in-Carrier®(CnC) Data Connections

The CA-0000275 cable bypasses the CRS-300 1:10 Redundancy Switch.

IMPORTANT

If Carrier-in-Carrier®(CnC) is utilized with any Traffic CDM-625, refer to Figure 4-9to connect and secure the PMSI Multi-drop CnC Plus Cable CA-0000275 (<11X> DB-9M, 8.25’) between the Redundant CDM-625 and any CnC-enabled Traffic CDM-625(s) as follows:

•DB-9F connector labeled “PMSI” on the Redundant CDM-625, to

•DB-9F connectors labeled “PMSI” on all CnC-enabled Traffic CDM-625(s).

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