Mocomtech operation manual CRS-300 110 Redundancy Switch Revision Introduction

CRS-300 1:10 Redundancy Switch	Revision 16
Introduction	MN/CRS300.IOM

The CRS-300 1:10 Redundancy Switch (referred to throughout this manual as the Switch) provides fully automatic protection of traffic circuits in the case of equipment failure. The user can configure the CRS-300 to back up (replace) a Traffic modem when a Unit Fault and/or a Tx/Rx traffic Fault occurs.

Intended for hub applications, the CRS-300 is compatible for use with the Comtech EF Data Modems specified in Table 1-1. While the Switch is capable of controlling any of these specified modems, note that it is important that only one type of modem may be connected within a given Switch system; this is because the redundant modem must operate identically to the configured traffic modem.

A key feature of the CRS-300 architecture is its ability to allow the redundant modem to ‘bridge’ a traffic modem. The Switch automatically configures the redundant modem to match the bridged modem’s configuration. The Switch also copies the bridged modem’s terrestrial transmit clock/data and routes it to the redundant modem. When using the CRS-280/280L, it additionally routes the bridged modem’s Rx IF. Because this live traffic is used at all times to verify performance, no external test equipment is needed to determine the health of the redundant modem.

Construction features: The CRS-300 is modular in construction – all replaceable modules insert into slots in the back panel. This includes the controller, Redundant Modem Interface (RMI), Traffic Modem Interfaces (TMIs), and Power Supply Units (PSUs).

Because power consumption is below 30 watts for a fully populated Switch, no fan cooling is required. Key Reliability Features: The CRS-300 incorporates the following key reliability features:

•Twin, independent, AC or DC power supplies.

•Traffic Modems with differing data types can all be supported by the Redundant Modem

– the exception to this is the CDM-Qx/QxL and, with some limitations, the CDM-625.

•Primary traffic paths are maintained, error-free, when power is removed.

•TMIs can be completely removed from the CRS-300, with cables still attached, and traffic is not interrupted or affected.

•RMI and/or TMIs can be replaced without disturbing other traffic circuits.

Interfaces: The CRS-300 supports all of the modems’ available interface types, which include EIA-530/-422, V.35, Sync EIA-232, ASI, Balanced or Unbalanced G.703, LVDS, Single-port Ethernet Bridge Mode, and HSSI.

Ease of Connection: Connection to the traffic modems and the redundant modem is remarkably easy – rack cabling is simplified and the number of potential failure points is reduced.

For the CDM-570/570L,CDM-600/600L, or CDM-625:When using the multi-protocol interface, only a single cable – carrying all data signals, alarm information and the serial remote control interface – is required for each modem.

If the G.703 interfaces are used: One additional cable is required.

For the CDM-Qx/QxL:These modems require an additional RS-485 multi-drop cable from the Switch to all modems to provide remote control interface capability.

For EIA-232/-485 M&C User connections: A direct user-to-modem serial EIA-232/-485 communication connection is not permissible when connected to the CRS-300. The user must instead connect to the DB-9 "Remote" connector on the CRS-230 System Controller (installed on

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