Events and alarms

Sequence control of process operations, and recipe/batch management and tracking. Alarm and device interlocking (often in addition to separate hard-wired systems). Event and alarm recording, and historical trend recording of process variables. 

A modem plant requires more information, events and alarms to be made available at the main control room than was generally the case in the past. This has been made much easier to achieve by the use of computer networking and fibre optical technology. Most of the information that is available at the switchboard can be transferred to the main control room so that, for example, a one-line diagram presentation can be made on a computer desk-top monitor (man-machine interface, MMI). 

Printers are useful to record the sequence in which events occur, diagnostics and other events and alarms, with time and date stamping and identification by tag number. Report formatting utilities should be provided. 

Inform patients who are receiving prophylactic therapy on the importance of its use, potential adverse drug events, and the possible alarm symptoms associated with PUD. 

Various simple and sophisticated fire and gas detection systems are available to provide early detection and warnings of a hydrocarbon release which supplement process instrumentation and alarms. The overall objective of fire and gas detection systems are to warn of possible impending events that may be threatening to life, property of continued business operations, that are external to the process operation. 

Undoubtedly, further integration of analytical processes (and particularly sample handling) will happen, which will make denser deployment possible. The widespread availability of effective and widely distributed monitoring of chemo- and bio-warfare agents will reduce the incidence of false alarms and copy-cat events, and may reduce the effectiveness of these weapons, which often rely on the fear of what might be present, rather than the reality. 

Event logging, a facility to record all notable events, including communication, exceptions, and alarms... 

In contrast to systems that are set up to transmit local only alarms when the sensors are triggered, systems can also be set up to transmit signals to a central location, such as to a control room or guard post at the utility, or to a police or fire station. Most fire/smoke alarms are set up to signal both at the location of the event and at a fire station or central monitoring station. Many insurance companies require that facilities install certified systems that include alarm communication to a central station. For example, systems certified by the Underwriters Laboratory (UL) require that the alarm be reported to a central monitoring station. 

System access security Diagnostic checks Operator interfaces Software installation verification Software backup and restoration Control and monitoring loop operation Alarm, event, and message handling Safety and operational interlocks... 

First, safety critical systems must be reliable. These systems control releases in the event of accidents. It s necessary to have a critical analyzer, instrument and electrical system test program. This should consist of preventive maintenance and alarm and trip device testing for panel alarms, emergency isolation valves and other critical components. [7]... 

Any alarm system used must communicate clearly the nature of the emergency event and its severity. In a Level One Emergency some people may have to be evacuated in order to ensure their safety, but by and large the emergency can be contained within the unit. In that case, information usually may be given to unaffected employees through normal telephone communications. 

Necessary actions have not been predetermined and documented when responding to alarms from the XXXX. .. [alarm events] are not recorded. .. There is no secondary review of alarm events, and any corrective actions are not recorded. [FDA Warning Letter, 2000]... 

The system is equipped with a telemetry control system and a fully automated backup system. Each bank of three irradiation chambers has two units on line at all times, with the third unit serving as a backup. In the event that the UV intensity decreases below acceptable limits (20,000 pW-s/cm ) in any of the chambers, the automatic butterfly valve will close, stopping flow through the chamber at that time, the automatic butterfly valve on the standby unit will open. The alarm system is also activated if UV intensity decreases below acceptable limits in any of the chambers. The UV alarm system is interfaced with the automatic dialer and alarm system. In 1987, total equipment costs for the six-unit UV irradiation system with butterfly valves was US 74,587. 

PROTECT, as currently implemented for WMATA, relies on human-in-the-loop response and decision making, except for the initial automated camera response triggered by sensors. Verification of detection, performed by staff in the operational control center (alerted to do so by the sensor alarm), is a necessary first step before any responsive actions are taken. CB-EMIS has been developed as a situational awareness tool where all event and supplemental (such as data on hazardous chemicals) information can be accessed and displayed. CB-EMIS also provides estimates of threat agent dispersion, the location of hazardous areas, and predetermined response strategies. These functions provide important inputs to the response decision making. 

In the event of a fire, fire detection and alarm systems allow for fire detection, early warning and evacuation of warehouse occupants and for alerting emergency responders and warehouse management. A fire detection and alarm system may also be utilized to automatically activate devices... 

Instrumentation and automatic control is desirable in plants of this size to allow for automatic shutdown and alarm in case events should occur during unattended periods which might be deleterious to the plant or the product water. Automatic startup, however, is not a requirement if there is adequate product water storage, if the startup procedure for the plant can be carried out in a short time, and if an operator is available on call. 

In addition, each hallway and each room should have an emergency ( panic ) button that will set off an alarm and by-pass the computer-controlled access system on each door. This system allows anyone to enter a laboratory when an emergency occurs that requires immediate assistance, or to leave the laboratory. Because pressing the button triggers a series of events and emergency responses and subverts security, it should only be used for a true emergency. 

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