| 摘要 |
<p>A known system for interconnecting a number of operators to a number of radios uses a computer to establish which one of the radios is available to provide a facility requested by an operator and then to connect that radio with an operator. The programming of a general purpose computer to do this job is very complex. Also it may be difficult for an operator to be sure that the computer is working correctly and a fault in the computer or its program can result in a complete breakdown of the system. The illustrated apparatus avoids these problems by using a control bus 5 and an audio bus 6 to interconnect operator positions 1 and 2 and radio positions 3 and 4. Each position 1,2,3 and 4 is allocated, by a timing circuit 7, time slots on the control bus 5 during which it applies digital words to the control bus indicating its own identity and information to be transmitted to other positions. …<??>Because data applied to the control bus by the operator positions 1 and 2 is time multiplexed, requests from positions 1 and 2 for a particular radio facility are dealt with turn by the radio positions 3 and 4 so that operators at positions 1 and 2 cannot compete for the same radio facility. In this way the need for a general purpose computer and its associated software is avoided. Furthermore, each radio at positions 3 and 4 is able to communicate to the operators at 1 or 2 its current mode of operations so that the operators can always be sure that the system is operating correctly. …<??>Another advantage of the illustrated system is that a malfunction at any one of the positions 1,2,3 and 4 does not cause a complete breakdown in the system. The only central component critical to the operation of the system is the timing circuit 7 and, in an alternative system, this could be replaced by individual timing circuits at each of the positions 1,2,3 and 4.</p> |
