Coded pulls were typically used in new fire alarm systems until roughly the 1950s, and then occasionally into the 1970s. Until the early 1990s, some panels were made with an extra zone to accommodate any existing coded pull stations. The GNU C Library: Setting an Alarm 21.5 Setting an Alarm The alarm and setitimer functions provide a mechanism for a process to interrupt itself in the future. Download or View Getting Started Guides Online Find this article at: -security/user-manual/Was This Article Helpful?
See Signal Handling. To be able to use the alarm function to interrupt a system call which might block otherwise indefinitely it is important to not set the SA_RESTART flag when registering the signal handler using sigaction. Turning the switch one way causes the notification appliances to sound continuously (or in the case of single-stroke bells, ding once). Turning it the other way and then activating the pull allows a silent test to be done in which the station’s mechanical parts are checked to ensure proper function. Previously, the old British standard did not allow hinged covers and plastic resettable elements. Function: unsigned int alarm (unsigned int seconds) Preliminary: | MT-Safe timer | AS-Safe | AC-Safe | See POSIX Safety Concepts. You can only have one timer of each kind set at any given time. If you set a timer that has not yet expired, that timer is simply reset to the new value. This call point uses a lever-shaped key to reset.
The return value is 0 on success and -1 on failure. Perhaps the most recognizable pull station is the T-bar pull, so named because the handle is shaped like the letter «T». This style is manufactured by many companies. Telephone jacks are visible beneath the open cover. They can form part of a manual alarm system or an automatic alarm system. Function: int setitimer (int which, const struct itimerval *new, struct itimerval *old) Preliminary: | MT-Safe timer | AS-Safe | AC-Safe | See POSIX Safety Concepts. You should establish a handler for the appropriate alarm signal using signal or sigaction before issuing a call to setitimer or alarm.