Jump to content
 







Main menu
   


Navigation  



Main page
Contents
Current events
Random article
About Wikipedia
Contact us
Donate
 




Contribute  



Help
Learn to edit
Community portal
Recent changes
Upload file
 








Search  

































Create account

Log in
 









Create account
 Log in
 




Pages for logged out editors learn more  



Contributions
Talk
 



















Contents

   



(Top)
 


1 History  





2 Purpose  





3 Activation procedure  





4 System tests  





5 Limitations  





6 References  














Emergency override system







Add links
 









Article
Talk
 

















Read
Edit
View history
 








Tools
   


Actions  



Read
Edit
View history
 




General  



What links here
Related changes
Upload file
Special pages
Permanent link
Page information
Cite this page
Get shortened URL
Download QR code
Wikidata item
 




Print/export  



Download as PDF
Printable version
 
















Appearance
   

 






From Wikipedia, the free encyclopedia
 

(Redirected from Local Access Alert)

Local Access Alert
TypeEmergency warning system
Country
United States, others
TV stationsSome broadcast television stations and cable systems

Broadcast area

Mostly areas that have not upgraded to the Emergency Alert System

Launch date

Unknown
DissolvedUnknown
ReplacedEmergency Bulletins
Replaced byEmergency Alert System

The Local Access Alert (also known as Local Access SystemorEmergency Override System) is a system designed to warn radio stations, television stations, cable television broadcast feeds or satellite signals of impending dangers such as severe weather and other civil emergencies. With a gradual transition from analog cabletodigital cable, the Local Access Alert has been phased out and largely replaced with the Emergency Alert System in the United States.[1][failed verification]

History[edit]

The first known Emergency Override Systems or Local Access Alerts were delivered during the boom of cable television in the 1960s,[citation needed] although it was not directly (and mainly) called the two main names of systems, as they sometimes pronounced it in various names. In the late 1960s and early 1970s, Local Access Alerts began to spread all over the United States, although few cities and towns had cable television yet. When cable systems continued to grow, the Local Access Alert was usually added.

Slide used during a test in 1982

Local Access Alerts gained the most popularity on local cable systems from the latter half of the 1970s until the end of the 1990s, when the Emergency Alert System took over the role of the Emergency Broadcast System on cable television on January 1, 1997. The Emergency Alert System began to build up on most cable television systems through the installation of then-new generators and encoders between 1997 and 1999. Some of the notable EAS generators at the time include Video Data Systems, Texscan, Gorman-Redlich, Idea/Onics, and Cable Envoy; and encoders include SAGE, TFT, and Trilithic models. During the cable growth of the Emergency Alert System, only some cable systems retained the Local Access Alert equipment up into the first part of the 2010s.

In the late 2000s and early 2010s, most remaining cable systems set up for Local Access Alerts used either both Trilithic EASyPLUS or Video Data Systems as their modern screens instead of the previously used older systems such as CommAlert (although older systems of the Local Access Alert were still used in a handful of areas at the time). By the end of the 2010s, the popularity of Local Access Alerts became nearly extinct on most cable systems in the United States, as all cable systems already had the Emergency Alert System, which at that time, local cable systems had become either Comcast, Time Warner Cable, or Suddenlink among others.

As of the early 2020s, most Local Access Alerts are delivered as practice or demonstration warnings as part of the Emergency Alert System, but the remainder of the nearly-extinct Local Access Alerts can still be seen on a minority of very small cable systems that either haven't had equipment upgraded or became part of a major company in unincorporated or very minor areas.

Purpose[edit]

Police or emergency management let cable viewers in local and surrounding areas know of an impending emergency and instruct them to shelter or evacuate. Alerts are chiefly for weather warnings for severe weather such as tornadoes, flash floods, earthquakes, winter storms, and hurricanes. Alerts may also pertain to Amber alerts, traffic closures, 911 outages, forest fires, dam failures, train derailments, and road conditions.

Activation procedure[edit]

The Local Access Alert is initiated by local law enforcementoremergency management staff, much like the antiquated Emergency Broadcast System, by dialing a number and entering a PIN through a telephone to take control of the cable of an area in the path of danger. Cable subscribers in that area have every television channel interrupted by audio and often a given screen. The distinct attention signal played can be Morse code, a siren, DTMF tones, steady single (or dual) tones, or multiple hi-lo beeps. The screen shown can be black, white, colored depending on warning, a slide or static. More modern alerts use a black screen with the words "Local Access Alert" in all capital letters with a message stating that "a local authority has initiated a direct community access"; the text was generated using the Trilithic EASyPLUS character generator (the same one used for the Emergency Alert System).

System tests[edit]

Tests of the Local Access Alert occur once weekly at randomly selected times, as well as scheduled monthly tests and yearly tornado drills. These alerts resemble the format used for activation of the Emergency Broadcast System and the Emergency Alert System.

Limitations[edit]

A limitation of the Local Access Alert system is that operators have to dial out to end transmission. Simply hanging up the phone connected to the system after an emergency broadcast does not work, and viewers may hear other phone noises – such as off-hook tonesordial tones – before cable programming resumes.

The newer Emergency Alert System employs Specific Area Message Encoding technology to activate for potential disasters and deactivate to resume cable broadcasts, especially late at night when many public servants aren't available to break in.

References[edit]

  1. ^ "Emergency Alert System". Federal Emergency Management Agency. October 30, 2023. Retrieved June 19, 2024.

Retrieved from "https://en.wikipedia.org/w/index.php?title=Emergency_override_system&oldid=1230018930"

Categories: 
United States civil defense
Disaster preparedness in the United States
Cable television
Warning systems
Hidden categories: 
Articles needing additional references from October 2023
All articles needing additional references
Articles that may contain original research from October 2023
All articles that may contain original research
Articles with multiple maintenance issues
All articles with failed verification
Articles with failed verification from June 2024
All articles with unsourced statements
Articles with unsourced statements from November 2023
 



This page was last edited on 20 June 2024, at 02:42 (UTC).

Text is available under the Creative Commons Attribution-ShareAlike License 4.0; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.



Privacy policy

About Wikipedia

Disclaimers

Contact Wikipedia

Code of Conduct

Developers

Statistics

Cookie statement

Mobile view



Wikimedia Foundation
Powered by MediaWiki