Abstract: A building alarm system includes addressable notification appliances connected to a system controller, with each notification appliance having a status indicator and an alarm indicator. The status indicator, such as an LED, provides for system test modes that avoid disruption of building occupants. To test the alarm system, the system controller selects which notification appliances to operate in response to a test alarm input and communicates to each selected appliance an instruction to operate its associated status indicator without operating its associated audible or flashing visible alarm indicators. In a troubleshooting mode, the system controller polls each of the notification appliances and receives an answer in response to the poll from any of the appliances. The controller operates the LED indicators of those appliances which answer the poll.

Abstract: An alarm system which includes multiple notification appliances for signaling an alarm condition. The system controller intelligently controls the notification appliances including notification devices such as an audible or visual alarm through multi-bit digital messages sent over common communication lines. The alarm system has both a supervisory or standby mode and an active mode of operation. In the standby mode, the notification appliances are powered at a first polarity DC voltage. In an active mode of operation, the first polarity voltage is reversed (or forward biased) to energize all the notification appliances on the communication lines. The system controller controls operation of the visual alarms by issuing synchronization signals, wherein the line voltage drops to zero, which trigger the visual alarms. An audible alarm command signal is embedded within the synchronization signal to control operation of the audible alarm.

Abstract: A monitoring system in an alarm apparatus includes a central panel for controlling operation of the alarm apparatus, first and second terminals, the second terminal including a communication device, such as a microcontroller, to communicate with the central panel. A communication link comprising fiber-optic cables is further provided to connect the first and second terminals. The first terminal includes a signaling device to signal to the communication device when there is a break in the communication link. Responsive to the signal, the communication device signals to the central panel that there is a break in the communication link. In accordance with other aspects of the present invention, a plurality of intelligent peripherals, such as detectors and audible and visual alarms, are connected and controlled by the central panel via the fiber-optic cables.

Abstract: A fire detection system cross correlates the responses of a temperature and smoke sensing units to achieve early-detection characteristics. The system also performs threshold-type detection on the smoke obscuration, temperature, and rate of temperature rise. If any of the thresholds are surpassed, the same alarm condition will be set. As a result, the detection characteristics of the resulting detector can be no worse than the conventional threshold-only systems. The system advantageously, however, provides for the early detection of fires that satisfy the cross correlation characteristics. Thus, it achieves the best performance characteristics of both approaches.

Abstract: A time recorder includes a digital display and a printer for printing selected information including time, date, comment and number. A removable cover covers programming text which surrounds the display. During programming, the cover is removed to expose the text and accept and change buttons which allow a user to accept or change entries in several printing and other categories. Programming entries are indicated either directly or through codes which are described in the programming text. Customized comments may be generated by a user. A character count is maintained on the display during programming. The display is inverted by the user to allow orientation of the time recorder for table or wall mounting.

Abstract: A method and apparatus detect devices on a line in an alarm system that have been assigned a common or duplicate address, or that are located beyond the maximum allowable wiring distance on the line, or that are poorly connected to the line thus providing weak answers to communications from the control panel. The method and apparatus operate by polling suspect addresses of devices on the line while adjusting the sensitivity of the receiver. The sensitivity of the receiver is lowered by an amount corresponding to the test being performed. In duplicate address testing, the sensitivity of the receiver is lowered by an amount such that a single response from only one device having the polled address will not be sensed, but combined responses from more than one device having the same address are sensed.

Abstract: In a building fire alarm system, the light strobes of a network of strobes are synchronized to flash simultaneously. Each strobe has a charging circuit to charge a capacitor which discharges through a flash tube. Once a capacitor is charged, the charging circuit is disabled. A synchronization pulse is applied through common power lines to trigger discharge of each strobe capacitor through the flash tube followed by recharging of the capacitor.

Abstract: An alarm system includes plural customer sites and first and second alarm monitoring stations. Each customer site has an alarm communicator for calling a monitoring station and transmitting an alarm message. The first and second monitoring stations are provided for receiving the alarm message through a telecommunications network. Each monitoring station includes an alarm processor system for processing the alarm message. Alternate routing in the network allows an alarm call to be rerouted from the first monitoring station to the second central monitoring station if the alarm call to the first station cannot be completed.

Abstract: A fire detection system cross correlates the responses of a temperature and smoke sensing units to achieve early-detection characteristics. The system also performs threshold-type detection on the smoke obscuration, temperature, and rate of temperature rise. If any of the thresholds are surpassed, the same alarm condition will be set. As a result, the detection characteristics of the resulting detector can be no worse than the conventional threshold-only systems. The system advantageously, however, provides for the early detection of fires that satisfy the cross correlation characteristics. Thus, it achieves the best performance characteristics of both approaches.

Abstract: In a communication system such as a fire detection system, individual addressable devices determine their addresses from address interface modules at the device locations. An interface module includes wire connectors for receiving system wires and a device connector. The interface module also includes jumper wires which serve as a readable address identifier adapted to be programmed to an address with installation of the module and to be subsequently read by the addressable device.

Abstract: A smoke/fire detector assembly having a base section with electrical contacts and a removable/attachable sensor section having corresponding electrical contacts. Each one of the electrical contacts is adapted to electrically contact a corresponding one of the base section electrical contacts. Each one of the electrical contacts has a threaded hole formed therein to receive an electrical contact screw. The hole has a projecting rim disposed about a peripheral portion. The base section has a plurality of recessed pocket formed therein for a corresponding one of the plurality of base section electrical contacts. Each one of the pockets has a pair of opposing sidewalls, a platform, and a resilient tongue-like member protruding into a region between the opposing sidewalls. Upper surfaces of the platform and the tongue-like member are disposed in a common plane spaced from the bottom portions of the sidewalls to provide a channel therebetween.

Abstract: A time recorder includes a digital display and a printer for printing selected information including time, date, comment and number. A removable cover covers programming text which surrounds the display. During programming, the cover is removed to expose the text and accept and change buttons which allow a user to accept or change entries in several printing and other categories. Programming entries are indicated either directly or through codes which are described in the programming text. Customized comments may be generated by a user. A character count is maintained on the display during programming. The display is inverted by the user to allow orientation of the time recorder for table or wall mounting.

Abstract: A dual-line time recorder includes a barrel cam, printer, motor, and slide plate. The motor rotates the barrel cam. The rotational motion of the barrel cam translates into lateral movement of the printer in forward and reverse directions. A slide plate is adapted for moving the printer in a transverse direction relative to the barrel cam between a first line of print and a second line of print. After printing in a forward direction along a first line of print, the slide plate shifts the printer for printing along a second line of print in the reverse direction. After printing in a reverse direction, the slide plate shifts the printer back to its original position. The printer is fully programmable for printing a variety of data on the print medium.

Abstract: In a pivoting time recorder, an inner frame is erected from a base. A printer assembly interfaces with the inner frame at a pivot. The pivot and printer assembly are suspended over the base, forming a slot for insertion of a document therebetween. The printer assembly includes a barrel cam having a protrusion adapted to interface with a cam follower integrated on the inner frame for raising and lowering the printer relative to the base about the pivot. The barrel cam induces axial movement in a programmable printer adapted to be driven by the barrel cam. A motor rotates the barrel cam for moving the printer axially and for raising and lowering the printer assembly relative to the base. The present invention operates with very little movement--only 2.degree. of rotation about the pivot point, resulting in a more reliable design having a lower manufacturing cost in comparison to time recorders of the prior art.

Abstract: A smoke detection unit has a detection chamber for sampling smoke from a surrounding environment. The detection chamber allows air circulation but is optically opaque. This configuration is typical of photoelectric smoke detectors, for example. A housing defines a window though which air from the environment circulates into and out of the detection chamber. The window's height is approximately the same as the chamber. A cage vane is positioned in the window and is configured as an inverted frustoconical member. An inner edge of the cage vane is spaced away from the chamber. The angled vane, along the other aspects of the unit's configuration, improves sensitivity by increasing smoke circulation through the chamber. This configuration guides the air currents typically created by fires at the ceiling so that the smoke flows easily into the detection chamber.

Abstract: An emergency strobe light for warning the hearing impaired of emergency situations includes a bulb extending outwardly from a base along an axis. Reflectors extending outwardly from the base direct a high percentage of light output from the bulb along a horizontal plane and a vertical plane which intersect each other along the axis of the bulb. The strobe light draws little power and can be powered by a battery.