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Basic System Components > Front-end unit

IT Flexibility

As has been demonstrated more than once in other sections of this webpage, an enormous number of the system´s functions depend on more or less sophisticated software algorithms. As any experienced IT engineer might anticipate, the software of the system may resemble a busy construction site for quite a while. This cannot be avoided, since many important features will have to be optimized during performance-testing of the system as a whole.

For the receiver and the central data processing, this will not be a problem. But what about the large number of front-end units that have already been installed in their final positions? Who would go out in the field and replace the EPROMs? No, that´s not the way to manage a complex IT project efficiently.

In order to avoid costly investment in manpower during beta testing, two provisions need to be made:

• the microcontroller system in the front-end must be designed so that the whole application software is resident in a protected portion of nonvolatile RAM
• the controller´s operational system must allow for easy downloading of new software through the RS-232 port (connected to a modem) or through the IrDA port

It would be a prudent decision to begin the installation of the system with a beta phase, where potentially some hundred sensors would be spread out all over the region, most of them with a more or less improvised connection to a public telecommunications facility. CDPD modems might be good candidates for this.

An additional advantage: in a preliminary set-up (connected to a standard phone service) it would be easy to evaluate the entire system by programming scenarios that would release a specified number of alert messages in a precisely determined time slot.