Yale Premium Alarm Hsa6400 Wirefree Alarm Kit

[mdf290]

To be able to prove that claim you would need to have accurate information about every attempted break in at every Yale protected house together with information about whether the alarm activated and at what point during the break in that the alarm sounded.

I am more than sure that had someone paid someone else to install an alarm and that if they were subsequently burgled and the alarm had not activated those persons would be very quickly onto the phone in an aggreived and aggitated condition asking why the hell the alarm had failed to work..

I personally have never had a single such phone call.... nor incidentally any calls asking why the alarm keeps false alarming but then I know how to fit them properly to make them work correctly.

 

[JohnD]

And yet the (im)probability that an interference signal will occur, close enough to block the sensor, at the same fraction of a second that a burglar forces entry, is something you take care to evade.

It is possible that you will win the lottery, or that you will be killed by a meteorite falling on your head. But not at all probable.

 

[Europlex]

( it was from from that other expert called yaleguy that I learn for the first time that sensors went to sleep ).

Bernard don't forget that mdf290 is the above mentioned.

 

[mdf290]

I have professional concerns about the reliability of alarm systems that depend entirely on one way wireless communication on licence exempt radio frequencies. These concerns are based on my 12 years employed designing equipment that had no alternative but to use radio due to one or more items being mobile.

I can see now why you are in effect overcompensating in relation to this issue.

A home alarm has a very static environment where the sensors range is fixed at the point of installation and the systems tested in situ.

You are using your experience of designing systems that needed to work critically in a mobile scenario where the levels of inteference and signal direction/strength and local topography could change at a moments notice and assuming the same level of uncertainty would exist in a static home environment.

Yes its possible that if you were to randomly keep movong your yale sensors around the house you would be capable of putting a sensor somewhere it would not work due to local conditions but that is why the system is tested to ensure it works properly.

The only outside influence then would be the local environment and yes if a taxi cab firm suddenly opens up next door and sticks up a 15mtre antenae yes you would be screwed.

Otherwise the threats are hypothetical and not in my experience of any significance.

As JohnD says you are saying that you should not fit a one way wireless diy system because it will fail when in actual fact all you should be saying is that there is a remote possibility that it will fail.

There is not a single home I visit where I am happy to let the home security be handled by one single device alone. Even if a hallway has a door sensor I promote a pir sensor as well as a backup and the same with all the ground floor rooms. I would never assume that a hallway sensor would be fine to protect your lounge as they would have to go through the hall to get in because they could come in the lounge window instead so again I promote a pir in every room with door or window access.
This reduces the chance of a system failing to operate to virtually zero as the likelihood of every sensor being blocked at that particular instance becomes a mathmeticians puzzle to actually calculate the probability of failure.

The chances of someone leaving home and forgetting to set the alarm in the first place is significantly expotentially higher than any probability of a properly installed one way wireless system failing.

 

[bernardgreen]

I am more than sure that had someone paid someone else to install an alarm

You don't pay some one to install a DIY alarm.

and that if they were subsequently burgled and the alarm had not activated those persons would be very quickly onto the phone in an aggreived and aggitated condition asking why the hell the alarm had failed to work..

Maybe not if they were told by a scenes of crime officer why it had not activated. Though they may have been interested why the person thay had paid to install an alarm had not pointed out one of the short comings of the alarm system he had recommended to them. ( don't worry, it was not a Yale alarm but one that has to comply with the same regulations )

II personally have never had a single such phone call.... nor incidentally any calls asking why the alarm keeps false alarming but then I know how to fit them properly to make them work correctly.

So why do Yale provide the option to inhibit the alarm when jamming is detected.

As Yaleguy3 posted

Switch 2 is rarely used in fact in 300 installations I have never had to use it at all.
This switch is used to turn off the signal jamming detection should local radio inteference be causing your siren to false alarm.

Read more: //www.diynot.com/forums/viewtopic.php?p=1669359#1669359#ixzz23JwZ6s1s

More accurate would be "I have never had to use it at all at the time of installation "

My alarm regularly sounds during the night, but there are no messages shown on the control panel. What is the reason for this?
This problem is usually caused by poor positioning of the external siren and will be exacerbated during bad weather, for example during periods of high winds and storms. Please place suitable waterproof packaging behind the tamper lever, also ensuring the siren cover is firmly screwed into place. If the problem persists it is also recommended to disable the radio interference detection.

Not my words. they are copied from http://www.yale.co.uk/en/yale/couk/Let-us-help/Alarms-FAQs/
Why would they suggest disabling the radio interference detection if radio interference was not a problem.

 

[JohnD]

What's your actual point, Bernard?

Are you saying "there is a theoretical possibility that one day, by amazing chance, a Yale alarm might fail to go off straight away because, at the fraction of a second that a burglar forces an entry, a nearby device sends a signal that prevents the alarm from going off"

Or are you saying "Yale alarms don't go off during a burglary because the signal doesn't get through"

 

[bernardgreen]

The only outside influence then would be the local environment and yes if a taxi cab firm suddenly opens up next door and sticks up a 15mtre antenae yes you would be screwed.

Not necessarily. The 15 metre antenna may be configured have a near horizontal propagation with very little power coming down to ground level until a mile or more from the mast. There are other less obvious sources of prolonged transmissions that would affect receivers.

As JohnD says you are saying that you should not fit a one way wireless diy system because it will fail when in actual fact all you should be saying is that there is a remote possibility that it will fail.

Noted. What I am saying is that people buying low cost easy to install alarms ( or any other equipment ) should be told of the un-avoidable compromises that are in the design of the equipment and what those compromises can result in. You should be doing that.

as the likelihood of every sensor being blocked at that particular instance becomes a mathmeticians puzzle to actually calculate the probability of failure.

It is the one receiver that is blocked. The transmitters can transmit as often as they can but if the receiver is blocked the system is dead. Even the manufacturers recognise this and while not shouting it from the hills they do put in a jamming detection function and sound the alarm if the system is jammed or blocked for more than ( is it ) 30 minutes. And then suggest turning this function off if there are "false" alarms that might be tamper alarms.

 

[bernardgreen]

Or are you saying "Yale alarms don't go off during a burglary because the signal doesn't get through"

In a one way wireless linked alarm system that complies with regulations applicable to the use of licence exempt frequencies if the signal to the siren is blocked then the alarm will not go off other than as a delayed tamper alarm. If Yale is one of those systems then the alarm will not go off if the signal doesn't get through due to blocking at the time of the burglar being detected.

How you prevent the signal getting through in a wired system ?

You cut the wire. Which will invoke a tamper alarm unless the thief knows how to cut without creating a tamper. That is possible but to get to the wire he has to first enter the building and his entry will have activated the alarm before he gets to the wire.

How you prevent the signal getting through in a wire-less system ?

You block the radio channel which after a delay will invoke a tamper alarm providing the tamper has not been dis-abled. Now how could a thief create a blocking signal ? What would he need ?

And please do not say that thieves are not able to work that out for themselves. Smash and grab ones might be too ignorant to work it out but then they will be content to smash grab the first valuable item they see and run even if there is an alarm sounding.

Thieves who want to spend some time looking around for small high value items are the type who are clever enough to know how to defeat the alarm before triggering any sensors.

 

[JohnD]

so you're saying "there is a theoretical possibility that one day, by amazing chance, a Yale alarm might fail to go off straight away because, at the fraction of a second that a burglar forces an entry, a nearby device sends a signal that prevents the alarm from going off"

and adding on "a skilled burglar can defeat various kinds of alarm, both wired and wireless"

and adding on "some burglars will take what they can despite an alarm going off, whether wired or wireless"

 

[bernardgreen]

Yes I did say that.

at the fraction of a second that a burglar forces an entry, a nearby device sends a signal

the nearby device could be transmitting continuously by intent or defect.

Do I also have to say the obvious which is that a semi skilled burglar can easily defeat many types of low cost wireless linked alarms before entering the building.

I can also add that a very skilled burglar could possibly defeat a top quality wireless linked alarm from outside the building but it would take several hours if not weeks of work to discover the complex two way communication protocol that he would have to replicate to defeat the system enough to enter the building with setting off the alarm.

 

[Europlex]

Here Bernard, seen these?

http://www.texe.com/uk/uploads/Ricochet_Technology_combined.pdf

What do you think?

 

[JohnD]

I think it's lovely that you enjoy talking about theoretical possibilities and insignificant probabilities

But you know very well that there is not much chance that a Yale alarm will fail to sound due to RF interference, at the very moment that a burglar forces entry.

 

[bernardgreen]

Here Bernard, seen these?

http://www.texe.com/uk/uploads/Ricochet_Technology_combined.pdf

What do you think?

Two way communication.

Sensors turned off when not required to extend battery life.

Sensors do not "go to sleep" until they are told to by the control panel.

When the first activation signal is blocked and the sensor does not get an acknowledgement reply it will repeat.

Many other safeguards in the protocol.

The "mesh" system suggests that every message has a unique message number to prevent one message echoing around the system. This would ( and probably does ) allow the control panel to detect lost messages and act as necessary.

Subject to the hardware being of satisfactory quality and a few more in-depth technical questions about how it works I would say this system is probably a very reliable one even in adverse ( radio ) environments.

 

[alumni]

I think it's lovely that you enjoy talking about theoretical possibilities and insignificant probabilities

But you know very well that there is not much chance that a Yale alarm will fail to sound due to RF interference, at the very moment that a burglar forces entry.

Whilst you just rely on blind faith that the technology and protocols in the grade one kit you are keen to promote will actually work - even when the manufacturer openly warns of the problem.

 

[JohnD]

Hello Alumni

Nice to see you here with your theoretical possibilities

Would you care the estimate the chances of two signals, each of a fraction of a second, occurring at exactly the same time, and both from devices close enough to be heard by the Yale receiver?

And for this to happen at the very moment a burglar sets off the first of the sensors as he enters the house ?