The capacity and complexity of today's operational equipment require intensive training to realize full system's capabilities. To meet that training need by stimulation of the device at the RF or video level could require hardware that exceeds the operational equipment in size and complexity. It is therefore necessary to explore alternative simulation architectures. One such possibility is to interface the simulation at the operational device computer. Since much of the functionality of current operational equipment resides in the algorithms programmed into the device computer, high fidelity of simulation can be achieved by interfacing at this point, since these algorithms are fully stimulated. In addition the simulation will be stable if there are upgrades to the operational program. The simulators may even be used to test the response of the changed algorithms to complex environments. This is less expensive than using full RF or video stimulation, and the resulting simulator is packaged more tightly. Therefore, this kind of simulation closely approaches the organic training concept.

To illustrate these points, the SLQ-32 simulation developed as part of the Perry Class Pierside Combat Systems Team Trainer, Device 20B5, will be used. Not only the strengths, but some of the pitfalls of interfacing a simulator to the device computer will be discussed. Methods of solution and tradeoff requirements are covered which result from such causes as real-time constraints imposed by the operational program, simultaneous control of the simulation by the host and device computers, and simulation validation. The results demonstrate that with proper design consideration a flexible, high fidelity simulation can be achieved by the use of this interface point.