Depending upon the application, the alarm output may be local, remote or a combination. Local alarms do not include monitoring, though may include indoor and/or outdoor sounders (e.g. motorized bell or electronic siren) and lights (e.g. strobe light) which may be useful for signaling an evacuation notice for people during fire alarms, or where one hopes to scare off an amateur burglar quickly.

Alarm systems incorporate a digital telephone dialer unit that will dial a central station via an available phone line and raise the alarm,  with an encoded message string that the central station decodes. These may connect to the regular phone system on the system side of the demarcation point, but typically connect on the customer side ahead of all phones within the monitored premises so that the alarm system can seize the line by cutting-off any active calls and call the monitoring company if needed. Alarm systems can be programmed to indicate which specific sensor was triggered, and monitors can show the physical location (or "zone") of the sensor on a list, which can make the resulting response more effective. For example, a water-flow alarm, coupled with a flame detector in the same area is a more reliable indication of an actual fire than just one or the other sensor indication by itself. Many alarm panels are equipped with a backup dialer capability for use when the primary form of communication is not functioning. The redundant dialer may be connected to a second phone line, or a specialized encoded cellular phone, radio, or internet interface device to bypass the phone line entirely, to thwart intentional tampering with the phone line(s). Just the fact that someone tampered with the line could trigger a supervisory alarm via the radio network, giving early warning of an imminent problem (e.g., arson). In some cases a remote building may not have phone service, and the cost of trenching and running a direct line may be prohibitive. It is possible to use a wireless cellular or radio device as the primary communication method.

Commonly used forms of backup communication that we use at C & B Alarms LTD. are:

• GSM (Cellular)
• Internet (IP)