Comtech EF Data RCS20 - Manual (Page 31)

RCS20 M:N Redundancy Switch Revision 15
Theory of Operation MN-RCS20 and CD-RCS20
3–1
Chapter 3. Theory of Operation
3.1 Overview
This chapter provides additional basic information on the RCU20, DDS20, and IFS20 hardware and
internal operation.
3.2 RCU20 Major Assemblies
The RCU20 Redundancy Control Unit contains the modules that control and monitor the operation of the
M:N Switch System. The RCU20 is composed of the following major assemblies and components:
• Central Processor Unit (CPU) Board
• Front Panel Board
• Controller Interface Module
• Clock Distribution Module (optional)
• Redundant Power Supplies
• Ethernet Module (optional)
• Bank Control Module
3.2.1 Central Processing Unit (CPU) Board
The Central Processor Unit (CPU) Board contains the M:N Switch intelligence and memory circuitry. The
on-board microprocessor is an MC68302, which has a 24-bit address bus and a 16-bit data bus. The
microprocessor controls and coordinates all major functions of the Switch and performs all necessary
calculations. The non-volatile system memory on the board stores the switching parameter settings for
each Modem Channel. Control and data signals are routed to the appropriate devices in the system
through various latches and transceivers that are controlled by the microprocessor.
3.2.2 Front Panel
Front panel controls and indicators provide for auto/manual configuration, as well as display of online/off
line status information for all modems in the Redundancy configuration. See Section 4.1
3.2.3 Controller Interface Module
The controller interface module (CPU TERR I/O) provides ports for external monitoring and control. See
Section 5.2.3.2.