NFPA 72-2002 11.7.6.7 Installations that include the connection of single- or multiple-station alarms with other input or output devices, such as but not limited to relay modules, remote signaling devices, phone dialers, security panels, heat detectors, and manual pull stations, shall be permitted, providing that an open or short circuit of the wiring leading to these input or output devices does not prevent normal operation of the single- or multiple-station alarm.