Abstract: A method for verifying operation of notification appliances on a notification appliance network during low input voltage conditions is provided. An output voltage is supplied to a network and is measured at a control panel. An input parameter is measured at a notification appliance connected to the network. A supply line impedance is calculated for the notification appliance based on at least one of the output voltage and the input parameter. At least one of the supply line impedance, the output voltage and the input parameter are used to determine a pass/fail condition for the notification appliance during a low voltage condition.

Abstract: A fire alarm system includes a fire alarm control panel (FACP) and an addressable signaling line circuit (SLC) operably coupled to the FACP for communicating with addressable components, including a plurality of sensors. The sensors can include a plurality of atmospheric sensors operably coupled to the SLC and each configured to provide information about their local atmospheric environment. Also provided is a mobile robot addressable and dispatchable by the fire alarm control panel (FACP) to an area indicated by sensors that are detecting a hazardous or potentially hazardous condition. The robot has mobile sensors that are configured to obtain verification of the hazardous or potentially hazardous condition and the robot is further configured to communicate the verification to the FACP.

Abstract: Mis-wired addressable loops are determined by enabling all loops and identifying all devices communicating on all loops. A list of all identified devices is recorded. One at a time, each loop is disconnected, a list of devices that are disabled is determined and recorded for the disconnected loop, and the loop is reconnected. When all of the loops have been processed, the lists of disabled devices are compared and those devices that are wired improperly are determined.

Abstract: A hazard alarm includes: a detector for detecting a hazard parameter; trigger logic; and reset logic. The trigger logic triggers an alarm state when the measured parameter reaches a predetermined trigger threshold. The alarm state is maintained until a reset is successfully performed. The reset logic, upon a reset command, resets the alarm state if the measured parameter is below a predetermined reset threshold, and inhibits resetting of the alarm state if the measured parameter is above the predetermined reset threshold.

Abstract: An alarm system includes a plurality of alarm devices connected to a load sensor. The load sensor senses the electrical load in the alarm system and indicates both the failure of the alarm devices in the system and the likely location of the failed devices.

Abstract: Jumper and ground faults are detected within an alarm system. Jumper detection applies to devices having two or more functions (e.g., audible horn and visual strobe). When operated with a single circuit, jumpers typically remain installed in such devices to provide power to all functions. However, if the devices are installed in alarm systems equipped with multiple functions, the jumpers should be removed to allow functions to operate independently and correctly. To detect unremoved jumpers, all loops to separate functions except one are isolated. After isolation, a predetermined signal is presented to the non-isolated loop and current is compared to a reference value. If jumpers exist between this non-isolated loop and another supposedly isolated loop, the additional parallel resistance produces an abnormal signal. To perform ground fault detection, lines of devices may be sequentially isolated (i.e., disconnected) at the control panel via software control until a previously detected ground fault disappears.

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 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.