CSD-3902

The CSD-3902 also offers enhanced reliability when compared to conventional master clock systems. When used in conjunction with the ACO-3901 automatic changeover module, the CSD-3902 sets new standards for reliability of master clock systems. The ACO-3901 automatic changeover unit can seamlessly switch between up to three CSD-3902 modules. In addition, a fully redundant CSD-3902 system (including two CSD-3902 modules and a ACO-3901 module) can occupy as little as 1RU of space, making it ideal for any application where reliability, density and performance are necessary.

Applications
The CSD-3902 should be utilized in any installation requiring time synchronization of clock displays and other devices.

The CSD-3902 is also ideal for use in ENG, OB van or mobile applications where space is at a premium. When installed in a 1RU configuration, the CSD-3902 occupies from 2RU to 5RU less space than conventional master clock systems. 3RU configurations of CSD-3902 can also be used effectively in space-restricted environments by allowing any additional modules to be installed in the same frame.

The CSD-3902 also offers other enhancements to maximize reliability including:

CCS™ — The CSD-3902 clock system driver can be controlled and monitored via Harris® CCS™ (command and control system). If a fault or alarm is detected, it can be instantly reported to the operator for immediate action via the CCS network. This minimizes the time necessary to respond to any potential problem.

DejaView — The CSD-3902 clock system driver can come equipped with Harris® DejaView state recovery feature. This will significantly reduce the downtime as-sociated with reconfiguring a new module.

Transparent Switching — The ACO-3901 features transparent switching between the primary and secondary CSD-3902.

Conventional autochangeover units will perform a non-synchronous switch from the primary to secondary master clock driver on detection of a fault. This hard changeover will be manifested as a discontinuity in the reference signals and result in a potential disruption to any downstream devices locked to the reference generator. With the CSD-3902 clock system driver, switchover of the unaffected CSD signal outputs will be transparent, with no discontinuities of the signal output. The  ACO-3901 passive switching relays will also ensure a continuous signal in the event of a total failure of either the primary or secondary CSD-3902.

Switching of up to three CSD-3902 modules — The ACO-3901, in addition to being able to switch two frame-internal CSD-3902-FM modules, can also switch a third external source through the external back module connections in the event of a failure of the primary CSD-3902; the secondary CSD-3902 will not be operating in failure mode without a backup.

Comprehensive monitoring and switching — The ACO-3901 can be configured to monitor and switch all of the output signals from its primary and secondary CSD-3902 modules. Conventional automatic changeover units typically do not offer switching of all of the outputs of their primary and secondary reference signal generators due to connector space limitations on the automatic changeover unit back panel. This represents a major compromise in reliability. The integrated architecture of the CSD-3902 clock system driver does not have this limitation.

Standalone power supply — The ACO-3901 comes equipped with an external DC power jack for use with the PWRSUPPLY-MTG external AC power adapter. This facilitates power supply redundancy in 1RU frame configurations.

Simultaneous configuration — The CSD-3902 clock system driver offers simultaneous configuration of the primary and secondary CSD-3902 modules. Changes in configuration to the primary CSD-3902 will immediately be reflected in the secondary CSD-3902. Identically configured primary and secondary CSD-3902 modules will minimize the potential for discontinuities associated with switchover from a primary to secondary reference signal source and simplify setup and maintenance.

Utilizing Nano-Lock technology, the MTG-3901 master timing generator and all NEO advanced reference systems are able to offer even greater precision, reaffirming Harris as the industry leadership in reference systems.

When the MTG-3901 is locked via the GPS-3903 GPS receiver or via the onboard modem, the time difference between its own internal timing engine and the reference time is calculated. Using this information, the MTG-3901 updates its output time and slews its blackburst output timing to correspond with the new timing data. This assures an accurate source of both time and blackburst.

Integrated reference systems that supply both timecode and blackburst without Nano-Lock technology can experience blackburst phase discontinuities during time synchronization. This is the result of a sudden shift in blackburst phase when realigning to new timing information acquired during the synchronization. Blackburst discontinuities are a potential source for disruptions for all downstream equipment within a facility.

In addition, the MTG-3901 uses this new timing information to make minute adjustments to its own internal timing engine such that after all timing adjustments are complete, the master frequency of the MTG-3901 timing engine is adjusted to compensate for variations from the reference source. The MTG-3901 system’s ability to self-discipline its internal timing engine assures that extended operation of the MTG-3901 will result in maximum precision.