Comtech EF Data CRS-500, Installation And Operational Manual

Page: 32 / 220

CRS-500 1:N Redundancy System
Revision 4
Introduction 1–8 MN-CRS-500
1.3.2 Data Switch Unit (DSU)
•
Chapter 3. INSTALLATION
•
Chapter 5. CABLES
AND
CONNECTIONS
•
Appendix B. CONTROLLER/TMI CONNECTORS AND PINOUTS
The front panel of the DSU can contain a maximum of 10 TMIs and one RMI. The DSU rear panel
provides two connectors for connection of the DSU to the CRS-500’s CSU and optional ISU.
The traffic data from the user interface to the Traffic Modem Interface passes through
normally-closed relay contacts on the TMI card. In the event that both power supplies are lost, or
if a traffic-carrying TMI and its cables are removed, no interruption of traffic data occurs.
The optional KT-0000072 DSU Rack Mounting Kit allows you to install the DSU into the rear or on
top of the rack in any of two horizontal or two vertical positions. This allows the unit to be
positioned or hinged outward, for convenient access to the RMI/TMIs when connecting cables
between the DSU, CSU, ISU, and the modems.
1.3.2.1 DSU Front Panel Operational Features
Figure 1-8 shows an operational example of a CRS-500 DSU front panel, as configured for 1:3
redundancy for the CDM-625/625A.
Figure 1-8. CRS-500 DSU Front View – CDM-625/625A 1:3 Configuration Example