Abstract: A method and apparatus multiplexing multiple alarm and head type values in a peripheral fire alarm device includes a head component for sensing the presence or absence of smoke or heat and a base component for communicating with the control panel. A communication interface between the base and head components with no more than three connectors for multiplexing the values between the head component and the base component. The control panel stores algorithms particular to each type of head which may be used to determine if an alarm condition exists. Using data received from the peripheral fire alarm device, the control determines which type of head component is currently installed at the base component and selects the correct algorithm.

Abstract: A monitor/control communication net with intelligent peripherals, that is, peripherals which are capable of monitoring and/or controlling various devices in accordance with messages received from a central panel cpu and which are also capable of reporting to the central panel the status of one or more devices monitored by the peripheral. Each peripheral is assigned a unique address by which it is polled by the central panel. All communication messages between the central panel and peripherals include a format code which indicates the nature of the message and the length of any data field in the message. Communication time is minimized by permitting the data field to vary in length from one peripheral to another, depending on the number and type of devices being monitored and/or controlled by the peripherals.

Abstract: Walk through test system for testing devices such as pull stations, smoke detectors, alarm bells and the like for alarm and trouble conditions without the assistance of a central panel operator. The devices are connected in a loop or loops distributed throughout one or more zones remote from a central panel. Alarm and trouble conditions are detected at the central panel. When a device is placed in alarm by the workman, a coded alarm is sounded which is aurally detectable by the workman at the location of the device, remote from the central panel. The coded alarm identifies the zone loop in which the device is connected. When a trouble condition is created in a loop by the workman, an alarm is sounded which is aurally detectable at the location of the loop, remote from the central panel. The alarm is coded to indicate to the workman that a trouble condition has been detected at the central panel.