CRS-300 1:10 Redundancy Switch Revision 16
Cables and Connections MN/CRS300.IOM
4–16
4.4 CDM-600/600L 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 MOD EMS.
I
MPORTANT
Traffic modems with differing data types can all be supported by the Redundant
Modem.
4.4.1 Control and Data Connections – CRS-300 to Modems
The 25-pin Control/Data Cable CA/WR0066 provides the EIA-422/-232/LVDS 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.
I
MPORTANT
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 signals using the CRS-340 TMI, and for HSSI with CA/TA signals
using the CRS-370 TMI. Refer to Chapter 4. MODEM, TMI, AND SWITCH
CONFIGURATION for this important configuration information.
Refer to Figure 4-7 to connect and secure the CA/WR0066 cables between each CDM-600/600L and
the CRS-300 as follows:
• DB-25M connector labeled “P1” on the RMI or TMI(s), to
• DB-25F connector labeled “P3B Data Interface” on the CDM-600/600Ls.
If G.703 is the traffic data type, also connect the CA/WR9038-6 data cable, 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 “P7 Balanced G.703” on the CDM-600/600Ls.