Yale Premium Alarm Hsa6400 Wirefree Alarm Kit

[bernardgreen]

The signal lasts for a fraction of a second.

If two sensors are triggered at exactly the same time, their signals may interfere with each other. This is not easy to achieve.

skipped over that bit, didn't you?

As the signal only lasts a fraction of a second it only needs a fraction of a second of signal from another transmitter to block the alarm signal. The chance is low but it NOT insignificant when you consider all the devices that are legally allowed to transmit on that frequency. With a wired system the alarm signal from the sensor is there as long as motion is being detected and unless the intruder has managed to "adjust" the wiring to block the signal it will reach the panel. Cutting the wires will set the alarm off.

The two big advantages of a DIY wireless system like the Yale is that it is cheap (especially if you buy it from a discount supplier like ironmongerydirect dot com) and that the householder can easily install it himself in an hour or so

Yes we know wireless appear cheap and is possibly bery easy to install. But these are more a marketing advantage than an advantage to the user in the long term.

It still does not mean it is as reliable as a system that is cheaper but more work to install. Wired systems can be made cheaper than an equivalent wireless system as they do not have the cost of wireless transmitters and receivers and the other costs incurred in hardware necessary to control the radio equipment and create the digital messages.

 

[JohnD]

"not easy to achieve" I said, and I stand by it.

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 ?

It would be a very optimistic burglar who expected that to happen. And a very lucky burglar if it did. He would be even luckier to get through the rest of the house without a detector seeing him, except at the very moment a neighbour's device was also transmitting.

 

[bernardgreen]

John

Open your mind to the fact that it is not only domestic alarm systems that use the radio frequency allocated for use by low cost DIY domestic alarms. Some of the other equipment that is legally using the channel can transmit for several seconds.

If it is not a problem then why do Yale have a jamming detection function built into the siren that sounds the alarm in the event of continuous activity on the radio frequency. If it was not a problem there would be no need for that function. And it has been said here that in the event of false alarms turning that function off will reduce the number of false alarms, but at the cost on the user not being aware that the system is compromised by jamming or blocking ( they are they same ) signals.

 

[JohnD]

"If it is not a problem then why do Yale have a jamming detection function"

weak argument.

If they didn't you would be grumbling that they should have.

Instead of grumbling that they do.

"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 ?"

No, you obviously wouldn't.

 

[bernardgreen]

John

There is no point in discussing this with you as you will only do your utmost to try to prove that DIY alarm systems using one way wireless communication are reliable.

Do you base your arguments on sound professional knowledge of how radio transmitters and receivers communicate and the protocols used to ensure that all information passed by wireless from unit to unit is correctly received or do you base it on the manufacturer's sales documentation ?.

For the lay reader the communication between sensor and siren in some alarm systems is similar to an injured person making just one shout for help and then, assuming it has been heard, quietly waiting for help to arrive. If no one hears the one scream help won't be coming ( the siren won't be sounding ). If you need help you keep calling until some one confirms they have heard you and have arrranged for the necessary help to be provided. Many wireless linked sensors cannot keep calling alarm because [1] it would drain the batteries, [2] it would prevent others from reporting alarms and [3] the regulations on use of the radio frequency do not allow it.

[1] As there is no communication to the sensor it cannot know if the alarm is set or not set so everytime it sees movement it has to send a message even if the alarm is not set. Hence after detecting motion it goes to sleep for a minute and sends no more messages while asleep.

[2] if the sensor did not go to sleep after the motion detected message has been sent then continuous movement of people in one room ( busy in the kitchen ) would result in continuous messages from that sensor which would compromise any messages from a sensor detecting an intruder breaking into another room.

 

[JohnD]

John

There is no point in discussing this with you as you will only do your utmost to try to prove that DIY alarm systems using one way wireless communication are reliable.

No, I will do my best to say that the DIY alarm is cheap and easy to install, and it is silly to whine that it is not as good as a more expensive one could be.

You know very well that the chance of an alarm failing in the way you describe is very small, you're just trying to baffle and frighten people who have a small amount of money and want a cheap and easy item.

Your point (2) is just a made-up objection since it does not happen. However, as you almost admit, in the very unlikely event of an interfering signal during the first "cry for help" the next device will also trigger a signal, as the burglar moves around the house.

I see you are determined not to address the improbability of a device in a neighbour's house causing an interfering signal at the very same fraction of a second as the alarm sensor is triggered by a burglar as he first enters a house. The probability is, as you know, infinitesimal, and it would, as you know, take a very optimistic burglar to rely on it. It would also, as you also know, take a stunningly fortunate burglar to actually have it happen. I wonder how often you win the lottery?

 

[bernardgreen]

John

To be honest it annoys me that systems are sold without the user's manual providing information about the limitations and hence functional compromises that one way wireless communication on a licence exempt frequency imposes on the system.

I see you are determined not to address the improbability of a device in a neighbour's house causing an interfering signal at the very same fraction of a second as the alarm sensor is triggered by a burglar as he first enters a house. The probability is, as you know, infinitesimal,

The probablity of an alarm whose design conforms to the requirements of the licence and whose modules are in good working order preventing another alarm reacting to an intruder is small but significant.

Now why do you not address the matter that there are many other wireless devices from door bells to car key phones that have to be considered when evaluating the possibility of an alarm being blocked.

You dismissed the jamming detection function. It is there to set the alarm off if an intruder knocks out the communication from sensor to siren by transmitting a continuous signal. Some people on this forum have mentioned repeated "false alarms" and have stopped them by turning of the "jamming detection". They were only false in that there was no intruder but they were genuine in that something had blocked the communication to the panel siren long enough for the panel or siren to consider the system was not able to detect an intruder so created an alarm condition.

 

[JohnD]

You know very well that the chance of an alarm failing in the way you describe is very small, you're just trying to baffle and frighten people who have a small amount of money and want a cheap and easy item.

I see you are determined not to address the improbability of a device in a neighbour's house causing an interfering signal at the very same fraction of a second as the alarm sensor is triggered by a burglar as he first enters a house. The probability is, as you know, infinitesimal, and it would, as you know, take a very optimistic burglar to rely on it. It would also, as you also know, take a stunningly fortunate burglar to actually have it happen. I wonder how often you win the lottery?

 

[mdf290]

Hmm this is shaping up to be another massive bernard borefest again.

Just to clarify an error that Bernard knowingly tried to mislead you with.

The sensors do not only transmit once before going into sleep mode so if an intruder activated a pir he would send more activation signals thus negating the possibility of concurrent signals even more.

Lets not also forget that the sensors within the home will be stronger signals than ones from the house over the road or even next door and therefore the local signals would BLIND your reciever to the other simoultaneous signals.

Lets just add this little note too...

I have personal experience of a thousand Yale installations and I have yet to encounter a single case where an alarm did not activate when it should have and that is in areas where Yale alarms were the commonest and most predominant system installed.

 

[henke]

Crikey that's a can of worms! Thanks for the input lads, for my question.

I'm think I'm gonna go for the wireless system, it seems to tick all the boxes and the disadvantages I can live with. Or at least I think I can, we live near a busy road and I'm concerned about spurious alarms caused by passing traffic. But I guess we'll have to suck it and see!

 

[Europlex]

I have personal experience of a thousand Yale installations and I have yet to encounter a single case where an alarm did not activate when it should ........

...... or did when it should.

 

[mdf290]

I have personal experience of a thousand Yale installations and I have yet to encounter a single case where an alarm did not activate when it should ........

...... or did when it should.

you have trouble with logic don't you...

If there was not a single case of an alarm failing to activate when it should then that means they all DID when they should...

To play devils advocate properly you need to understand the point you were trying to make..

 

[JohnD]

I'm concerned about spurious alarms caused by passing traffic.

What makes you think that will happen? If you buy a Yale, it "learns" the electronic serial number transmitted by each of your sensors, so that it can identify that a signal comes from one of yours, and not from anything else.

I fitted a 6400 in my old mums house, it was cheap to buy, and very quick and easy to install. To me those were very important factors. The only time we had a problem with signal being blocked was when we had steel scaffolding erected in the hall and stairwell, between the extra keypad and the panel. I will guess you won't be having that often, but during installation you can move things around if there happens to be a mass of metal or electrical equipment in the way. There is no cable to rerun, so moving things is easy.

Some of the professional alarmers on here hate DIY alarms and will tell you all sorts of things to put you off

how did I know that would happen?

 

[bernardgreen]

Just to clarify an error that Bernard knowingly tried to mislead you with.

The sensors do not only transmit once before going into sleep mode so if an intruder activated a pir he would send more activation signals thus negating the possibility of concurrent signals even more.

Yes I said one activation signal before going to sleep, ( it was from from that other expert called yaleguy that I learn for the first time that sensors went to sleep ). Even if it sends two or three activations close together before going to sleep then the problem remains the same. It ceases sending activation signals and goes to sleep not knowing if the activation signal reached the panel or siren.

Lets not also forget that the sensors within the home will be stronger signals than ones from the house over the road or even next door

In most cases that will be true but may not be true if the transmitter in the other house has a higher ERP than those in the system ( ERP effective radiated power )

I have personal experience of a thousand Yale installations

Which suugest that you might have a commercial interest in them

and I have yet to encounter a single case where an alarm did not activate when it should have and that is in areas where Yale alarms were the commonest and most predominant system installed.

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.

 

[bernardgreen]

Some of the professional alarmers on here hate DIY alarms and will tell you all sorts of things to put you off

how did I know that would happen?

I am not a professional alarm installer and I do not hate DIY alarms. I have over many years installed a few DIY alarms.

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.