how does an addressable fire alarm work?
360446
In the same way that data is sent serially in to / out of a serial port, each of the many devices connected to the same set of wires listens for it's own address (sequence of letters or numbers) and the message that follows. If the message is 'addressed to it', then it will reply, if not it ignores it.\n\nIt's a bit like having a pipe with lots of people with their ears pressed to holes drilled in a single pipe, listening for their own name. The controller shouts down the pipe saying 'Bill, what is the smoke concentration where you are?', Bill shouts back the answer... The controller then asks the same question to Fred, then to Ann, then to Sarah... Then back to Bill again... The address is just like having different names for the different devices.
317868
well for my physics project for the boards i made a photoelectronic burglar alarm- at the heart of this was an LDR( Light Dependent Resistor) when the beam of light is obstructed (think laser in the movies-lol) the LDR resistance rises and the circuit inside is set into oscillation and the alarm sounds- other good projects would be a rain alarm, a rectifier, an electroscope,..... the possiblities are endless- i suppose you could do anything involving electric circuits since thats what the cbse calss 12 physics text covers most- i doubt ud want to do anything on ray or wave optics
218684
The "stay" function is for when there is going to be someone moving around in the house.  It arms only the perimeter of the house.  Any entrance into the house (doors, windows) that has a sensor should set the alarm off if it is breached.\n\nIf you set your alarm to "stay" and you are able to open the door without triggering the alarm either that door doesn't have a sensor, or it is not operating correctly and will need to be serviced.
1149126
sure try norton. bt i ll advice u to get zone alarm personal edition for the task. it is free and fully functional.
854327
Contrary to popular belief, most agencies now scramble their radio transmissions and you may end up getting only the Fire department. \n\nAren't we terrible? \nWe have to keep the bad boys from hearing when we are coming for them.
702055
I would think that the centralized reporting has improved due to computerization.  Before, you would just hear an alarm going off.  Now, the security company knows exactly where the alarm was tripped and can notify you via phone, email, IM and pager.
888345
Zone Alarm is good and free\n\nwww.zonelabs.com
255004
go to http://home.howstuffworks.com/doorbell2.htm plenty of information there
524232
I use Zone Alarm for a firewall. It has an option to lock and unlock internet acess.\n\nhttp://www.zonelabs.com/store/content/home.jsp
966702
This is just simply from thinking, but here is my hunch.\n\n1.) It usues multiple sensors ie, sonar, cameras to align itself to the parking spot.  These sensors calculate distance, have the ability to get a visual on the targeted spot etc. Then the programming takes the rest.  \n\n2.) It's all about the sensors you have! Ask yourself this question...How does a heat seaking rocket follow a target?\nSensors sensors sensors! and a bit of programming of course!
217263
u can download a alarm software which plays mp3 as alarm\ni recommend download.com\nor search this software (wake up news)
788128
I use Zone Alarm firewall, and Avira Antivir guard.\nIn combination they work very well.\nYou can get Zone alarms from\nhttp://www.zonelabs.com/store/content/company/products/znalm/freeDownload.jsp\n\nand Avira from\nhttp://www.free-av.com/
88519
I hear Zone Alarm is ok, but I rather just have McAfee firewall and virus protection.\n\nAt any rate, just follow the instruction when setting it up. When in doubt, go for the defaults. As you restart your computer, Zone Alarm's fire wall will be asking you if you want this program or that program to access the internett (for example Internet Explorer). Select what your sure of and the rest you can deny access (you can always change it later if you find out that an application needs to go online to get infomation)
459061
There is probably a hardware difference in the modem which allows this.  The newer modems protocol supports things like call notification with caller id.\nAlso, internet security applets have a function to disable/enable internet at will, i don't know if this is what u mean by stand by.
139623
Directly addressing them will be really hard. If the device is a filing system you can manage it in the usual file-system way. If it's something else there are usually libraries for handling such devices, either specifically from the device manufacturer, or generically from MS.\n\nFor example cameras and other graphical input devices can be accessed through MS' media libraries.\n\nCustom weather balloon devices ship with their own libraries.
572638
If you have Windows XP SP2, you will see the Firewall option in your Control Panel.  If you don't have SP2, then you don't have that firewall. \n\nI recommend the FREE version of Zone Alarm, rather then getting the Windows SP2 upgrade from that Windows firewall.\n\nVisit http://www.zonelabs.com and  check out Zone Alarm at Download.com   CHECK the ratings and how others feel about it.
268345
Most states require a certain number of acres with a certain number of people before the issue can be brought to a vote.  I don't believe it can be done under what you're describing.  One other thing to remember is that once an area incorporates that area then becomes responsible for police, EMS, fire, water, etc that are handled by the county for unincorporated areas.  It'd suck calling 911 and having no one answer since you don't have 911 service!