Abstract: A communications system and protocol are described for wirelessly interconnecting a pair of bed and wall units that communicate the patient information, including bed exit alerts, from the patient supporting equipment to the hospital nurse call system. A linking procedure is provided for establishing a communications link to interconnect the pair of units, wherein the communications link fails upon detection of a third communications device simultaneously undergoing the link attempt mode. In one embodiment, the system provides for advanced collision detection by monitoring corruption of the end-of-packet byte within the periodic check-in message sequences between the linked units to prevent data corruption and future collisions. To ensure prompt interconnection of units, embodiments of the invention provide for a link reminder to alert the health care provider to initiate the steps for linking the bed and wall units whenever two or more unlinked units are in proximity.

Abstract: A communications system and protocol are described for wirelessly interconnecting a pair of bed and wall units that communicate the patient information, including bed exit alerts, from the patient supporting equipment to the hospital nurse call system. A linking procedure is provided for establishing a communications link to interconnect the pair of units, wherein the communications link fails upon detection of a third communications device simultaneously undergoing the link attempt mode. In one embodiment, the system provides for advanced collision detection by monitoring corruption of the end-of-packet byte within the periodic check-in message sequences between the linked units to prevent data corruption and future collisions. To ensure prompt interconnection of units, embodiments of the invention provide for a link reminder to alert the health care provider to initiate the steps for linking the bed and wall units whenever two or more unlinked units are in proximity.

Abstract: A communications system and protocol are described for wirelessly interconnecting a pair of bed and wall units that communicate the patient information, including bed exit alerts, from the patient supporting equipment to the hospital nurse call system. A linking procedure is provided for establishing a communications link to interconnect the pair of units, wherein the communications link fails upon detection of a third communications device simultaneously undergoing the link attempt mode. In one embodiment, the system provides for advanced collision detection by monitoring corruption of the end-of-packet byte within the periodic check-in message sequences between the linked units to prevent data corruption and future collisions. To ensure prompt interconnection of units, embodiments of the invention provide for a link reminder to alert the health care provider to initiate the steps for linking the bed and wall units whenever two or more unlinked units are in proximity.

Abstract: A communications system and protocol are described for wirelessly interconnecting a pair of bed and wall units that communicate the patient information, including bed exit alerts, from the patient supporting equipment to the hospital nurse call system. A linking procedure is provided for establishing a communications link to interconnect the pair of units, wherein the communications link fails upon detection of a third communications device simultaneously undergoing the link attempt mode. In one embodiment, the system provides for advanced collision detection by monitoring corruption of the end-of-packet byte within the periodic check-in message sequences between the linked units to prevent data corruption and future collisions. To ensure prompt interconnection of units, embodiments of the invention provide for a link reminder to alert the health care provider to initiate the steps for linking the bed and wall units whenever two or more unlinked units are in proximity.

Abstract: A communications system and protocol are described for wirelessly interconnecting a pair of bed and wall units that communicate the patient information, including bed exit alerts, from the patient supporting equipment to the hospital nurse call system. A linking procedure is provided for establishing a communications link to interconnect the pair of units, wherein the communications link fails upon detection of a third communications device simultaneously undergoing the link attempt mode. In one embodiment, the system provides for advanced collision detection by monitoring corruption of the end-of-packet byte within the periodic check-in message sequences between the linked units to prevent data corruption and future collisions. To ensure prompt interconnection of units, embodiments of the invention provide for a link reminder to alert the health care provider to initiate the steps for linking the bed and wall units whenever two or more unlinked units are in proximity.

Abstract: A communications system and protocol are described for wirelessly interconnecting a pair of bed and wall units that communicate the patient information, including bed exit alerts, from the patient supporting equipment to the hospital nurse call system. A linking procedure is provided for establishing a communications link to interconnect the pair of units, wherein the communications link fails upon detection of a third communications device simultaneously undergoing the link attempt mode. In one embodiment, the system provides for advanced collision detection by monitoring corruption of the end-of-packet byte within the periodic check-in message sequences between the linked units to prevent data corruption and future collisions. To ensure prompt interconnection of units, embodiments of the invention provide for a link reminder to alert the health care provider to initiate the steps for linking the bed and wall units whenever two or more unlinked units are in proximity.

Abstract: A signaling system may include two subsystems that share a common wiring backbone and provide public awareness functions. The two subsystems may be a public address system and a master/slave clock system. Remote rooms at the tail end of the wiring backbone include a speaker and a slave clock. The speakers are in communication with a control device through the wiring backbone. The slave clocks are in communication with another control device at the head end of the wiring backbone. The master/slave clock system superimposes its DC power signal and a time correction signal on the wiring backbone. Each slave clock interfaces the wiring infrastructure through a center tap of a speaker transformer which allows the slave clock to be powered and corrected via the speaker wiring infrastructure.

Abstract: A signaling system may include two subsystems that share a common wiring backbone and provide public awareness functions. The two subsystems may be a public address system and a master/slave clock system. Remote rooms at the tail end of the wiring backbone include a speaker and a slave clock. The speakers are in communication with a control device through the wiring backbone. The slave clocks are in communication with another control device at the head end of the wiring backbone. The master/slave clock system superimposes its DC power signal and a time correction signal on the wiring backbone. Each slave clock interfaces the wiring infrastructure through a center tap of a speaker transformer which allows the slave clock to be powered and corrected via the speaker wiring infrastructure.

Abstract: A lightweight, portable hand tool is provided for applying an insulation-piercing electrical connector, having insulation displacement conductive elements, to an insulated electrical cable. The tool is made of injection molded, impact resistant plastic and includes a manually grippable frame, with a loading die on the frame for receiving and holding the insulation-piercing electrical connector. A manually actuable, movable portion of the frame moves relative to electrical connector to cause the insulation on the wires to be pierced and thereby electrically connected to the connector. The tool is suitable for use with electrical cable having one or more pairs of wire, such as the typical four pair Ethernet cable.

Abstract: A signaling device for annunciating in a hallway of a building a status of a monitored person or object is provided. The signaling device includes at least two vertically stacked sections for announcing a status of the monitored person or object with each section announcing a status of a different condition. Each section includes a solid-state, light-emitting device (LED) that is supported such that when the device is mounted to the wall of the hallway a beam of light from the LED is substantially aimed at a wall opposing the wall to which the device is mounted. A pair of opposing planar surfaces extends along diverging planes and is supported over each LED to receive the LED's beam of light. Each of the planar surfaces extends at an angle approximately equal to a characteristic optical beam angle of the beam of light.

Abstract: A system and method for generating and presenting a lesson plan comprising audiovisual materials to a classroom. The system enables the automatic connection of audiovisual output signals from one or more audiovisual resources to classroom monitors in accordance with a predetermined sequence called a "lesson plan." The lesson plan includes labels for identifying selected ones of the audiovisual resources, and control commands for controlling the selected audiovisual resources. At a scheduled date and time, the lesson plan is loaded into the system and processed to automatically connect the output signals from selected audiovisual resources to specified monitors, and also to control the playback of the resources.The system also includes a software program for generating the lesson plan and saving it for a future presentation. To assist with the generation and presentation, a database of available materials and a scheduling program are also provided.

Abstract: An apparatus and method is provided for limiting the connection time of selected telephone lines in a private branch exchange (PBX) telephone system to telephone numbers dialed therefrom. A maximum connection time is programmed into the system for selected lines. Calls are automatically terminated if the duration of the call exceeds the maximum time. The selected line is prevented from re-dialing the called number for a certain period of time. If desired, the selected telephone line is automatically enabled and disabled by the system at predetermined times. The telephone system may also incorporate other conventional features for certain ones of the telephone lines in the PBX system, including limited prefix dialing capabilities, limited area code dialing capabilities, blocking of incoming calls, and the like.

Abstract: A system for monitoring the integrity of speakers and their associated wires using the pair of audio wires without disconnecting the speaker from the audio source. A direct current is injected onto the audio signal path and directed via a high impedance path through the speaker coil while any audio signals present drive the speaker through a low impedance path. The magnitude of the direct current is then evaluated at a central switching location and based on the value of the current, the status of the signal path is known to be either a good path, an open path, a shorted path or a grounded path. Alarm initiating devices may be connected to the wire pair and can be connected in such a way that the current on the wire pair indicates the status of the alarm indicating devices distinct from the currents corresponding to signal path integrity.

Abstract: A multi-link communication system includes a number of stations and interconnecting audio links under the control of a central computer. Each station is addressable by the computer for connecting selected stations to a selected audio link for establishing audio communication between stations. Each station has at least one corresponding access circuit for establishing an audio connection to a selected or preassigned link, and the connection is maintained by a corresponding memory circuit that is addressable by the computer. A group of output lines from the computer are used as select inputs to an analog multiplexer connecting a bidirectional control line to the selected access circuit for connecting or disconnecting the corresponding station and also for receiving connect or disconnect requests from the corresponding station. In a particular embodiment, the stations include multi-link dial and dialless telephones, single-link dialless telephones, and intercom speakers in an automatic private branch exchange.

Abstract: A user-programmable clock is provided for executing events defined by functions executed at a particular time and selected zones and for selected schedules. The clock includes an event memory for receiving zone and schedule data from a keyboard by way of a processor wherein the event memory is segregated into first, second and third tiers of event data. The processor of th clock is responsive to the keyboard for routing zone and schedule data entered from the keyboard to one of the three tiers of the event memory. The first tier of the event memory includes a plurality of locations wherein each location corresponds to an increment of time. Means are provided for selecting data stored in the first tier of the event memory at address locations corresponding to time data received from a timing mechanism. Means are also provided for selecting the appropriate data stored in the second and third tiers.

Abstract: A master/slave clock system including a slave clock configured for inexpensive and reliable control from the master. Each slave clock has an unregulated d-c supply adapted to be supplied with a-c power from the master clock. Threshold switching means in each slave clock is coupled across the d-c supply to sense an abnormally low d-c voltage level intentionally created by lowering the a-c supply level from the master. The threshold switching means switches the clock from the normal operating mode to the set mode where time is incremented at a predetermined rate for a duration controlled by the master clock in order to controllably set all slave clocks in the system to the correct time of day. The system conveniently allows all slaves to be reset to the same time when time is reset at the master, provides for automatic recovery after power failures, and provides a convenient means for automatically resynchronizing all slave clocks twice a day.

Abstract: A user programmable clock which is both simple to program and capable of executing relatively complex events. The front panel has a display divided into a plurality of functional blocks, with an operator positionable pointer adapted to activate any block. A single keypad is used to enter data in the respective blocks designated by the pointer. The system allows programming of comparatively complex events, capable of relating a single time to any combination of days and any combination of zones. Event programming is further simplified by providing an immediate indication of an erroneous entry along with a signal distinguishing between various potential types of errors.

Abstract: A feedback elimination apparatus for a sound system which employs a notch filter assembly comprising a plurality of active notch filters, each capable of producing a narrow notch in the frequency characteristic of the system. Means are provided for temporarily switching each notch filter to an oscillating mode to produce a reference signal at notch frequency which, for adjustment purposes, is zero beat with an acoustic feedback signal in the system, so the feedback signal is canceled when the notch filter is returned to its normal mode. A compressor is temporarily interposed in the sound system for limiting and controlling the level of the acoustic feedback signal to facilitate separation of acoustic feedback signals of different frequency and to prevent overload.

Abstract: An administrative telephone system for use in schools, hospitals and the like which includes a dialable administrative telephone set and a plurality of dialless remote or "staff" telephone stations having identifying numbers, interconnected by a central exchange. The administrator can dial any staff telephone station by pressing two digit buttons on the dial pad. Associated with the administrative telephone set is a digital display device having a column of display positions. Each staff telephone station has a call-in switch. The central exchange includes storage provision coupled to the digital display for registering and displaying, in order, the numbers of the staff telephone sets which have called in and thus have indicated a desire to communicate with the administrator.

Abstract: An input amplifier stage for a microphone which includes a transistor having a load circuit including a load resistor and an emitter resistor. In a preferred embodiment, using a transistor of the NPN type, a volume control potentiometer is provided having a first terminal which is coupled to the emitter and a second terminal which is coupled to the output of the stage, with the wiper being grounded so that (a) when the wiper is adjacent the emitter, the emitter resistor is effectively shunted by low resistance thereby increasing the gain of the transistor stage while leaving the output terminal substantially free of shunting effect for maximizing the output signal, and so that (b) when the wiper is adjacent the output terminal, the stage output terminal is effectively shunted by a low resistance while leaving the emitter resistor substantially free of shunting effect for decreasing the gain of the stage and minimizing the output signal.