Mocomtech CDM-570/570L Modem Connections, Control and Data Connections CRS-300 to Modems

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

4.3CDM-570/570L Modem Connections

If adding a modem to an operating 1:N system, care needs to be taken to not interfere with the existing Traffic Modem. The cabling, 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.

Traffic modems with differing data types can all be supported by the Redundant Modem.

IMPORTANT

4.3.1Control and Data Connections – CRS-300 to Modems

The 25-pin Control/Data Cable CA/WR0066 provides the EIA-422/232 traffic data path and serial communication path between the Switch and the modems, and is therefore always required even if the data type is G.703.

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, DTR/DSR signal using the CRS-320 (obsolete) or CRS-340 TMI. Refer to Chapter 4. MODEM, TMI,

IMPORTANT AND SWITCH CONFIGURATION for this important configuration information.

Refer to Figure 4-6to connect and secure the CA/WR0066 cables between each CDM-570/570L and the CRS-300 as follows:

•DB-25M connector labeled “P1” on the RMI or TMI(s), to

•DB-25F connectors labeled “Data Interface” on the CDM-570/570Ls.

If G.703 is the traffic data type, also connect and secure the Data Cable CA/WR11999-6, used for either Balanced or Unbalanced G.703 data, as follows:

•DB-15M connector labeled “P2” on the RMI or TMI(s), to

•DB-15F connectors labeled “Balanced E1/T1” on the CDM-570/570Ls.

4.3.2User Data Connections – CRS-300 to User

The User’s traffic data from multiplexing equipment or a test data generator should connect to the connectors labeled “User Data Interface” on the TMI(s). This interface replaces the direct connection to the Traffic Modem’s “Data Interface” connectors.

1. Because the Redundant Modem’s function is to replace a faulted Traffic Modem, the RMI does not have a User Data Interface.

IMPORTANT 2. Ensure that the correct operation for Balanced or Unbalanced G.703 data is configured on the modem.

For T1/E1 operation, the optional CN-0000268 T1/E1 Adapter (illustrated in Figure A-32in Appendix A. CABLE DRAWINGS) may be purchased from Comtech EF Data to adapt the Balanced G.703 DB-15F connector on the User data side of the TMI to a RJ-48 female connection.

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