Adaptation Process

DDS supports a very wide range of interface types. Over the past 7 years we have added 2-4 new interfaces each year and the library is now extensive. Most new interface types that we see are variants of those that we already have. But how do we find out the differences and how do we adapt the DDS to each case?

Site Visit

The first step is a site visit. Here we examine any available documentation and attach test equipment to the exchange to determine the basic parameters. Following that we look at the protocols used for data transfer so that we can create a full description of the tape system operation.

The site visit normally lasts from as little as one day for simple fact finding, to as long as two weeks if we are planning to complete the implementation and testing during the same visit.

Documentation and Reverse Engineering

If exchange documentation is available this often provides interface details and pinouts. While it seldom includes detailed timing information it is often enough to save considerable time with test equipment trying to work out the basic details.

Where documentation is missing or unclear, we use a wide array of high-end test equipment to detect pinouts, sample pins at speed and determine the protocols and signalling in use. The success of this draws heavily on our experience and knowledge over many years.

Test Equipment

We travel with logic analysers, high speed scopes and other test gear which allows us to monitor over 100 signals simultaneously at sample rates of 1GHz or more. This test equipment provides a clear picture of what is going on in the interface at the lowest level. With this equipment we can understand proprietary extensions and changes introduced by vendors to standard protocols such as SCSI. It also allows us to deal with the precise timing which can make the difference between a successful emulation implementation and an unreliable solution.

Protocol Analysis Software

We have built up a formidable arsenal of protocol analysis software for SCSI, Pertec, Kennedy, Cook and other interface types. These interfaces can pass thousands of operations in a matter of seconds, with millions of signal transitions. Getting to the core of all this data quickly is a challenging task. Withour software toolkit and logic analyser link software we can locate a complex interaction problem in minutes instead of days. 

Testing and Homologation

It is critical that the DDS operation has been fully proven and tested by the end of the homologation process. We work closely with engineers at our local partner and at the operator company to define a series of tests which comprehensively cover the required operation modes. Backup, restore, CDR / billing collection, tape operations and external media are tested using the same processes as employed for the legacy tape drive. Unusual situations such as network failure, emergency restart, power failure and cable error recovery are checked as part of a comprehensive test plan.

Skilled and Experienced Engineers

The key to our success is our skilled and experienced engineers. With vast experience of telecoms environment, the best available tools and the ability to work under pressure, our team is assured of a successful result.