This self-paced online course covers the allowable methods for transmitting fire alarm system signals to supervising stations. The use of circuits in the protected premises is reviewed in this course only as they apply to off-premises signaling.

Upon completion you should be able to:

• List the allowable methods of signal transmission
• Understand different methods of signal transmission, including multiplex, subsidiary station, supervising station, repeater, transmitter, and receiver
• Explain how various fire alarm signal transmission methods work, including McCulloh system, active multiplex, directly connected, digital alarm communications system, two-way RF multiplex systems, one-way private radio, directly connected non-coded systems, and private microwave radio systems

Who Will Benefit

Anyone whose job involves designing, reviewing, evaluating or installing fire protection systems, including: designers, installers, engineers, electrical contractors, technicians, project managers, fire marshals, and architects.

Course Summary

• Signal transmission is critical to a complete fire alarm system in a building that is not constantly occupied, or which has a hazard that merits close monitoring from the fire alarm system. If the transmission means fails, there is no notification of the problem at the protected premises.
• A number of transmission methods are available, but many are not widely used. In today's technology, digital communications is most widely used. It involves a digital communicator and a digital receiver and uses passive communications over the public switched telephone network. 
• Additionally, radio frequency transmission is widely used, but mainly in municipal systems and auxiliary station fire alarm systems.
• NFPA 72 still recognizes all of the methods of signal transmission, as there may be some of the other methods employed, but not on a significant basis.