Starting the simulation environment with an input deck allows the evaluation of arbitrary tasks, taking full advantage of the functionality of the VLISP interpreter and all other modules. The input deck contains LISP code to define process flows (see Section 5.9), to create parameterized tasks (see Section 8.9), and to submit simulation jobs.
To establish a communication mechanism with the VISTA/SFC environment even in detached operation, i.e., without connection to a terminal or a display, and without using socket connections, a simple, file-based, one-directional data transfer mechanism has been implemented. A temporary input file is loaded by the environment upon reception of a signal (Figure 6.10).
Figure 6.10:
Simple signal-based remote control mechanism.
Signals are used to initiate reading input files during detached operation.
The input file can contain any statements valid in an input deck and provides a simple means of inquiring status information, viewing available results, and starting or halting operation of the detached process.