Abstract: A dispatcher console for use in a digitally trunked, multisite public service radio system. The dispatcher counsel comprises a personal computer having a co-processor logic board, an audio switching tower, and user I/Os including a customized keyboard, display screen, audio speakers, headset and a transmit foot pedal. The switching tower routes audio communications between the console and multisite switch. The tower is controlled by and connected directly to the co-processor board. The customized keyboard is also connected directly to the co-processor board and has dedicated keys for commonly performed functions. The display screen presents information in a standard format such that the dispatcher knows precisely where to find particular information.

Abstract: A dispatching console system (20) for handling communications transmissions includes a main processor (50) and a co-processor (52). The main processor (50) receives external console control commands which specify a desired settable (i.e., connect/disconnect) relationship between audio devices in communication with the console and issues main processor commands to the co-processor (52). The co-processor (52) controls a switching circuit (72) in an audio tower (24). The switching circuit (72) is a matrix of cross-point switches (220) which connects and disconnects selected communication devices. In addition to the main processor commands, desired settable relationships between audio devices can also be mandated by device activation input signals which are applied through the audio tower (24) to the co-processor (52).

Abstract: A communication link for a dispatcher console to a multisite network of RF digitally trunked radio site transceivers and other dispatcher consoles. The communication link provides the dispatcher console direct access to a wide area RF network. A multisite central switch establishes audio and control communications between the different sites and various dispatcher consoles. The dispatcher consoles have audio and control links to the multisite switch. The multisite switch has a distributed architecture in which a switch node interfaces with the dispatcher console. A control communication protocol provides a standard format for message packets between the multisite switch and dispatcher console.

Abstract: An electronic security device has at least one lock and a control center for generating keys to the lock. When a new key is generated, a new (second) combination is generated by applying a predetermined algorithm and randomly generated (first) calculation data to the previous (first) combination. To calculate a next new (third) combination, another randomly generated (second) calculation data is applied to the second combination using the same algorithm. The control center stores, on the key, the third combination, and the second calculation data used to obtain it and the first calculation data used to obtain the second combination. At the lock, the third combination is compared with a stored combination and if there is no match, the lock calculates a possible second combination by applying an algorithm, which is the inverse of the predetermined algorithm, to the stored combination using the second calculation data read from the key.