Abstract: In a fire alarm system, a message is sent on a pair of power lines to a notification appliance. The notification appliance responds to the message by activating one or more of its notification devices. In a standby mode, only enough power is supplied to the plural notification appliances, at a first voltage level, to support two-way communications between a system controller and the notification appliances. In an active mode, power is supplied at a second voltage sufficient to operate audible and visible alarms of the notification appliance. The notification appliance may include an addressable speaker. The addressable speaker connects to and receives messages over the pair of power lines, has plural taps for selecting audio power. In response to a command, a selector in an addressed smart speaker selects a tap to select a particular audio power.

Abstract: A power supply system includes a power supply; a load coupled to the power supply via a power supply line to receive a voltage therefrom; and a circuit protection device. The circuit protection device includes at least one switch device coupled between the power supply and the load on the power supply line; a first controller coupled to the at least one switch for: A. monitoring current flow through the at least one switch; B. maintaining the at least one switch in an ON state while current flows through the at least one switch in a first direction; and C.

Abstract: A system and method for determining a fault threshold for an operational module according to the model of the operational module are described. The system includes an operational module, a storage unit, and a monitoring unit. The operational module has circuitry for producing a characterization signal with an electrical characteristic that uniquely correlates to the model of the operational module. A storage unit maintains an association between at least one parameter value and a fault threshold. A monitoring unit is in communication with the operational module to receive the characterization signal and with the storage unit. The monitoring unit measures the electrical characteristic of the characterization signal to derive a parameter value therefrom and accesses the storage unit to determine the fault threshold associated with the derived parameter value.

Abstract: An improved power supply subsystem, which is automatically updatable, includes a first power supply having a first power circuit, a first controller adapted to control operation of the first power circuit, a first interface adapted to connect the first controller to an external device, and a first bi-directional peer-to-peer port. The power supply subsystem further includes a second power supply having a second power circuit, a second controller adapted to control operation of the second power circuit, a second interface adapted to connect the second controller to the external device, and a second bi-directional peer-to-peer port.

Abstract: An improved redundant computing apparatus includes a chassis assembly configured to (i) mount to a standard electronic equipment rack and (ii) consume substantially 1U of space in a particular direction (e.g., vertical height) within the standard electronic equipment rack. The chassis assembly includes a housing and a midplane disposed within the housing. The apparatus further includes a set of power supply/blower assemblies configured to connect to the midplane of the chassis assembly through a front of the housing in a field replaceable manner, and a set of computing devices configured to connect to the midplane of the chassis assembly through a back of the housing in a field replaceable manner. By way of example, the set of computing devices is adapted to move data into and out of a set of disk drives on behalf of a set of external host computers.

Abstract: A data storage system includes a disk drive assembly having a plurality of disk drives, a first processor for controlling access to the disk drive assembly, a second processor for controlling access to the disk drive assembly, a first power supply for supplying power to the first processor and to the disk drive assembly and a second power supply for supplying power to the second processor and to the disk drive assembly.

Abstract: In a highly available environmental monitoring system, several slave devices are associated with either a fast polling list or a slow polling list. The fast polling list is polled by a master device more frequently than the slow polling list. A slave device is associated with the fast polling list if the slave device responds to a poll from the master device within a time period, and is associated with the slow polling list if the slave device does not respond to the poll from the master device within the time period. Furthermore, several control devices arbitrate to determine which shall be the master device for controlling several serial buses. The master device periodically switches between the plurality of serial buses to communicate with slave devices.

Abstract: In a fire alarm system, a message is sent on a pair of power lines to a notification appliance. The notification appliance responds to the message by activating one or more of its notification devices. In a standby mode, only enough power is supplied to the plural notification appliances, at a first voltage level, to support two-way communications between a system controller and the notification appliances. In an active mode, power is supplied at a second voltage sufficient to operate audible and visible alarms of the notification appliance.

Abstract: An alarm system is provided 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 communication lines. The alarm system has both a standby and active mode of operation in which communication between the controller and notification appliances is possible in both modes of operation. In the standby mode, the notification appliances are powered at a first voltage level. Communication between the notification appliances and the system controller is provided by sending data pulses along the communication lines relative to the first voltage level.

Abstract: An amplifier assembly includes a heat sink and a plurality of amplifier stages, where the total power rating of the amplifier stages is greater than the power rating of the heat sink. The heat sink can have a power rating of 50 watts and can include two amplifier stages, each having a power rating of 50 watts. In an alarm system, each amplifier is able to power one or more selected alarm loops. One of the plurality of amplifier stages acts as a backup amplifier for any of the other amplifier stages in the event of an amplifier stage failure. Also, the amount of power produced by the amplifier stages is flexibly controlled by the alarm system.

Abstract: An alarm system is provided 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 communication lines. The alarm system has both a standby and active mode of operation in which communication between the controller and notification appliances is possible in both modes of operation. In the standby mode, the notification appliances are powered at a first voltage level. Communication between the notification appliances and the system controller is provided by sending data pulses along the communication lines relative to the first voltage level. In an active mode of operation, the first voltage level is raised to a second voltage level.

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: 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 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: An output voltage supplied to alarm devices in an alarm system is adjusted according to either a standby condition or an alarm condition. In the standby condition, a power control circuit adjusts power so that a standby voltage is supplied to the alarm devices which allows the alarm devices to respond to poll messages regarding their alarm status. An alarm condition is triggered when an alarm device responds with an alarm status indicating an alarm condition. During an alarm condition, the power control circuit adjusts power to provide a higher voltage to the alarm devices in order to allow additional alarm device functions to be operated.

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.