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.