A second case worthy of discussion is an installation at a site having computer room facilities shared by a DEC-VAX cluster and a separate network of assorted UNIX platforms running SUN-OS and various BSD and System-V derivatives.

As the area to be protected is large and the enterprise is non-homogeneous, two independent Disaster Prevention Systems were chosen for the site; one protecting the DEC-VAX/VMS cluster and its local area and the other protecting the UNIX network and its area. From a practical matter, it was recognized that if one DPS should sense an environmental threat to the area, then the other should have a similar interest and may be able to verify the finding. Having no simple software link between the VMS and UNIX host systems, a cross link between the two SAM 3010's were created by cabling a relay output from one unit to an input port of the other unit, and vice-versa. Thus, when one SAM 3010 indicated the detection of an irregular condition, it would toggle the relay output sending an alert signal to the other SAM 3010.

Also recognized was the fact that both systems would have a mutual interest in detecting water or smoke/fire conditions in the room, and that economies would be realized by having them share access to the same groups of these detectors, rather than employing separate water and smoke detection systems for each SAM 3010/Host platform. The Synthesized Voice Auto-Dialer is also shared between the two DPS's.

Each of the two SAM 3010's is supported by independent Humidity, Air-Flow and Temperature Sensors. To provide cross-verification and some degree of redundancy, the Temperature Sensors for each system were placed in alternating positions across the longest room dimension. Using this technique, it is possible for managers to cross verify the readings from these sensors, as the SAM 3010's report from any one sensor should not vary significantly from the reports of the two adjacent sensors connected to the other SAM 3010.


The techniques employed here satisfied several important goals for the computing facility:


The cost savings achieved by the sharing of various resources makes the acquisition of Disaster Prevention technology a fiscal possibility.

CASE #2:

Supporting Non-Homogeneous Environment with 2 DPS Front-End-Processors Yields Cross-Verification, High Reliability and Savings through Redundancy.

Alternating of Monitoring Zones in Dual-DPS Environment Yields Improved Area Coverage with Cross-Verification.

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INTRA COMPUTER, Inc. , 2005-Present