Abstract: A baud rate detector determines the baud rates of signals received by a selective call receiver. If the signals have no detectable baud rate or the baud rate of the received signals does not match that of a plurality of known selective call network transmission baud rates, the selective call receiver indicates to its user that it is out of range of the network's transmitters.

Abstract: A paging network which generates pages at a page source storing a plurality of subscriber files chosen from subscriber files stored at a plurality of switches located in the network. The destination to which a page is to be transmitted is determined by the network transmitting the page to the switch storing a number identical to the identification added to the page by the page source. A plurality of locations may be connected to the network with each location generating pages having a different type of information.

Abstract: A pager (1) includes switches (12,13,14,15) for setting the priority of a message expected to be received at a predetermined time on a substantially continuous carrier signal. A receiver (3) is then activated for a period of time determined by the priority setting prior to the expected time of the message. The length of the period of time is greater for a higher priority setting so that if the carrier signal is not detected, an alert is indicated either visually (9) or audibly (10) giving the user time to place himself into range of the carrier signal. Furthermore, the pager (1) may operate in a reduced power mode prior to the predetermined time.

Abstract: An apparatus and method for monitoring the status of a multiple part vehicle. An apparatus according to the invention comprises a tag for placement on a second part of the vehicle. The tag communicates a unique ID code to an interface unit on the first part of the vehicle. The interface unit detects the presence of a valid ID code, and in response, provides an indication that the second part of the vehicle is connected. A transmitter provides data indicative of the connect/disconnect status of the vehicle to a central station. Vehicle position data may also be provided to the central station.

Abstract: A trunked communication system wherein some of the communication resources are preassigned for exclusive use only by a predetermined group, such as a public safety agency. In addition, to assure optimal assignment of communication resources, communication resource assignments are made pursuant to a methodology that minimizes usurpation of unused resource capabilities.

Abstract: A keyless electronic combination lock is adaptable for placement on a door, and operates independently of any other locks and without a central control system. The lock has a keypad for entering combinations, a random access memory (RAM) into which the entered data is loaded, a microprocessor, and an electrically erasable programmable read only memory (EEPROM). One or more entry codes for opening the lock are stored in the EEPROM and loaded into the RAM when the lock is powered-up. To open the lock, one of these codes or a master entry code must be entered at the keypad. Each entry code can be individually prevented from opening the lock by entering a corresponding individual lock-out code. All of the entry codes can be locked-out by entering a master lock-out code, by entering all of the individual lock-out codes or by throwing a dead bolt. The master entry code works regardless of the lock-out status and regardless of the dead bolt. To change lock-out status, the lock-out code is simply reentered.

Abstract: A tone code identification system identifies a stolen computer every time the same is turned on. Police, on recovering a stolen computer, can call a central registry and transmit the tone code to reveal the identity of the rightful owner.

Abstract: A synchronous distributed measurement system in a digital computer network comprising a master node and a plurality of slave nodes interconnected by communications links to form a ring. The master mode includes a message transmitter for transmitting a synchronizing message over a communications link. Each slave node includes an operational portion for performing selected operations. A message receiver receiving the synchronizing message from a communications link, and a message transmitter responsive to receipt of the synchronizing message for retransmitting the synchronizing message over the communications link. An operational control portion starts the measurement portion a selected delay time after the message receiver receives the synchronizing message, the delay time providing that the operational portions of the slave nodes perform the measurements in synchronization.

Abstract: A paging receiver has an indicator capable of illluminating in one of a plurality of colors. The color of illumination is selected in response to the address received by the pager. The indicator identifies the address by the color illuminated. The indicator also indicates weather a message is protected, read, about to be protected or about to be deleted by the color and color sequence of the indicator. The color indicator also indicates if the paging receiver is about to be turned off. The indicator may also serve as a back-light for a display when the paging receiver includes a display. Signals within the information to be displayed may change the color or change the intensity of the back-light, these signals may also turn the back-light off or on.

Abstract: A programming unit (1) for ON-OFF switching of a siren or similar warning device can be provided with remote actuation capability by connecting it to a radio receiver tuner (27) and radio data signal decoder (25). The output of the signal decoder (25) is connected to a block decoder (12). Some of the block decoder outputs are connected to a comparison circuit (8) which attempts to match a broadcast siren address with a stored address uniquely identifying the associated siren program unit (1). In the event of a match, a set of flip-flops and gates controls loading of information at other block decoder outputs into a siren program buffer memory (4) and then into an end memory (3) attached to and controlling the program unit (1). After a siren program is performed, end memory (3) is reset.

Abstract: An alarm system includes a controller and a plurality of transponders having different addresses. Certain of the transponders include switch means for monitoring conditions, and latch circuits to retain memory of the switch conditions. The controller includes means for positive recognition of a latched alarm or trouble condition in any transponder, before the clear-alarm signal or clear-trouble signal is sent from the controller to restore the alarm circuits to their original states. This insures that an alarm or trouble condition at a transponder is not "missed" by inadvertent clearing before a positive recognition is registered in the controller.

Abstract: A system whereby the operating power for a series of sensor elements and their status may be reported along a single twisted pair connecting line. The connecting line is protected from addition or deletion of the required sensors to insure the security of the connections. The system has the ability to determine the connection of added sensors, even when they share common identification information.

Abstract: A pager receiver includes at least one lock-out circuit, an out-of range circuit, and a single timer coupled to the lock-out and out-of range circuits and responsive to timing signals generated by the pager for generating an initiated one of either the lock-out timer interval or out-of range time interval. Each lock-out circuit of the pager receiver corresponds to an address function programmed therein and is activated by the function detect signal generated in response to the initial decoding of the corresponding address function to initiate the generation of the lock-out time interval by the single timer and to inhibit the corresponding alert annunciation from responding to subsequently generated function detect signals corresponding thereto for the duration of the lock-out time interval. The single timer is also initiated to generate the out-of-range time interval at the generation of each sync pulse timing signal by the pager receiver, but only in the absence of an activated lock-out circuit.