Yale Premium Alarm Hsa6400 Wirefree Alarm Kit

[JohnD]

More theoretical posturing from Bernard.

But the only question that really matters, which has been asked repeatedly, he won't answer.

"What is the probability that an interfering signal will block a sensor at the same fraction of a second that a burglar breaks in to your house?

 

[mdf290]

Of course all the tests you mention would have been the self same or similar tests the manufacturers put the systems through when designing them and their experts far more knowledgeable than I and indeed possibly you passed the systems for production and the open market.

 

[alumni]

Of course all the tests you mention would have been the self same or similar tests the manufacturers put the systems through when designing them and their experts far more knowledgeable than I and indeed possibly you passed the systems for production and the open market.

A bold assumption. Sadly a very wrong one too on both product and skill sets.
Don't for one minute think Manufacturers always do rigorous field testing. It's surprising how many products only get bench tested.

 

[bernardgreen]

But the only question that really matters, which has been asked repeatedly, he won't answer.

"What is the probability that an interfering signal will block a sensor at the same fraction of a second that a burglar breaks in to your house?

The probability that an interfering signal will block a sensor at the same fraction of a second that a burglar breaks in to your house can only be accurately calculated if there is accurate information about channel occupancy and relative signal strengths at the time the burglar breaks into the house.

The interfering signal may be several seconds long, it may even be as long as the entire time the burglar is in the house. As we all know from Yale Guy and mdf the continuous interference from a broadband router prevents the alarm system operating as intended.

Probability that an interfering signal ( from a poorly located router ) will block a sensor at the same fraction of a second that a burglar breaks in to your house appears to be close to 100%. Now John answer this question, if a router that does not operate on 433.xx MegHz can disrupt an alarm system what over equipment that does not operate on 433.xx MegHz can interfere with a wireless linked alarm system. ? ( relates to the pass band of the receiver and harmonics of other signals ). And what equipment operating on 433.xx MegHz is legally allowed to operate ?

 

[bernardgreen]

Don't for one minute think Manufacturers always do rigorous field testing. It's surprising how many products only get bench tested.

Ironically the equipment that is rigourously tested to ensure compliance with the regulations applicable to licence exempt operation is the equipment most prone to problems from activity on the channel. It doesn't blast excessive power from its transmitters and it doesn't hog the channel with multiple repeats to reduce the chance of a packet ( message ) being lost.

The other requirement they try their best to comply with is that the equipment must act in a satisfactory manner in the presence of interfering signals. This is not difficult to achieve ( provided the interfering signal is from a compliant source ) when battery economy can be ignored.

"Satisfactory manner" is a compromise between what is needed and what can be achieved given the need to have a long battery life and use of a licence exempt radio frequency.

Compelled signalling where a packet is repeated if not acknowledged from the destination is one way to cope with spasmodic interference but manufacturing cost is increased.

The ignorance of some "installers and sellers" is a worry. One vendor talking about low cost DIY wireless alarms with battery powered sensors said that battery life in the sensors depended on how often and how long the alarm was set. Wait for it,

""the sensors are only active while the alarm is set"".

That is possibly true in systems where the control panel can tell the sensors to switch off. But not a possibility in one way wireless linked systems.

 

[mdf290]

The ignorance of some "installers and sellers" is a worry. One vendor talking about low cost DIY wireless alarms with battery powered sensors said that battery life in the sensors depended on how often and how long the alarm was set. Wait for it,

""the sensors are only active while the alarm is set"".

Was that the full quote? maybe you are mistaken about what the person meant by that. ie that the sensors will only set the alarm off when it is set.
However battery life is NOT a problem unless someone thinks regular replacement in the region of 18month-2 yrs at a cost of 75p per sensor and a five minute job is too arduous.

They are likely the same people who let their smoke alarms fail.

You just can't help some people.

 

[JohnD]

But the only question that really matters, which has been asked repeatedly, he won't answer.

"What is the probability that an interfering signal will block a sensor at the same fraction of a second that a burglar breaks in to your house?

The probability that an interfering signal will block a sensor at the same fraction of a second that a burglar breaks in to your house can only be accurately calculated if...

Alternatively, it can be observed by experiment and real-life examples, like I've seen and mdf has seen.

Theoretical postulating about what might conceptually happen under certain potential circumstances being of little help in calculating the probability of a real-life event.

So my real-life observation of zero failures in 10,000 signals from the "entry" sensor, and a break-in rate of once in thirty years, combine to give a vanishingly small probability. Added to which, a burglar will have to be very optimistic to hope that the day he breaks in, he will be lucky enough to catch the fraction of a second when the signal is blocked.

Luckily, if the panel is installed on top of a router which constantly blocks the signal, the householder has a very good chance of noticing that his alarm never works, and can easily rectify it by moving one or other of the devices.

 

[bernardgreen]

Alternatively, it can be observed by experiment and real-life examples, like I've seen and mdf has seen.

So you both set up a transmitter and receiver with two counters... one to count number of packets sent and the second to count number of error free packets received. I doubt very much that you did.

Theoretical postulating about what might conceptually happen under certain potential circumstances being of little help in calculating the probability of a real-life event.

Dismissing real life events is a good way to make the calculation result favourable for the sale of another system.

So my real-life observation of zero failures in 10,000 signals from the "entry" sensor,

You actually observed each and every one of those entry sensor signals. I doubt it.

he will be lucky enough to catch the fraction of a second when the signal is blocked.

I do not believe that you are so blinkered, ignorant or stupid that you believe interfering signals will only last a fraction of a second. If that was really true then the jamming detection function would never see jamming yet at least one manufacturer suggests turning that feature off if there are too many instances of the alarm reporting jamming has been detected.

Luckily, if the panel is installed on top of a router which constantly blocks the signal, the householder has a very good chance of noticing that his alarm never works, and can easily rectify it by moving one or other of the devices.

And if it is close enough that it only blocks it occasionally then on a "good" day the alarm will work ( so the router is not seen as a problem ) and then on a "bad" day the "innocent" router blocks the signals rendering the alarm useless.

If the router is blocking the panel than the panel needs to be moved out of the near field effect of the routers radiated power. Moving a sensor closer to the panel may work as it will increase the signal the panel sees from the sensor and if it is then stronger than the routers near field effect the sensor will be "heard".

 

[JohnD]

Alternatively, it can be observed by experiment and real-life examples, like I've seen and mdf has seen.

So you both set up a transmitter and receiver with two counters... one to count number of packets sent and the second to count number of error free packets received. I doubt very much that you did.

no, Bernard, that's very silly of you. I observed if it always worked in practice, or if it ever failed to work,

That's the nitty-gritty of what really matters. Your fanciful speculation is just airy-fairy guesswork.

Go on, take a stab at it. One in a million? One in ten million? One in a hundred million?

 

[bernardgreen]

John why do you persist....

The answer has been given, you do not like it, so you keep asking in the hope that you will be given the answer you want to hear. All you will hear from me is the answer you NEED to hear.

But one more time.

THE RISK OF LOSING AN ACTIVATION SIGNAL IS DEPENDENT ON WHAT EVER ACTIVITY IS PRESENT ON THE CHANNEL AT THE TIME THE ACTIVATION SIGNAL IS TRANSMITTED.

On a remote island with only one house the risk is negligable. ( assuming no ships pass by using equipment on the channel )

 

[onecare]

If the router might be you a problem with your wireless equiptment.
Get a HARD WIRED system ! Instead of winging on about it .

A hard wired system is always a better option as if a wireless manufacturer goes out of buisness you may be stuck without being able to get replacement parts and need to change your panel again .


The castle caretech enforcer is a good system , we fit those on all wireless jobs .

 

[Europlex]

After all this time I still can't get my head around having a business that CHARGES to fit a DiY system that can be bought in most DiY shops!

 

[JohnD]

More theoretical posturing from Bernard.

But the only question that really matters, which has been asked repeatedly, he won't answer.

"What is the probability that an interfering signal will block a sensor at the same fraction of a second that a burglar breaks in to your house?

The answer has been given

No it hasn't, you have never answered this question, and you never will, because you don't want to admit that the probability is vanishingly small.

 

[bernardgreen]

After all this time I still can't get my head around having a business that CHARGES to fit a DiY system that can be bought in most DiY shops!

Simple equipment. low cost and dealing with customers who probably read only the hype on the box and are un-aware of the compromises that result from the use of one way comms.


This is interesting reading......

http://www.pyronix.com/enforcer-wireless-control-panel.php

 

[denso13]

After all this time I still can't get my head around having a business that CHARGES to fit a DiY system that can be bought in most DiY shops!

People want the service and are obviously willing to pay for it. should that not be allowed? The "elderly" discount system is regularly abused with pensioners buying all sorts to receive their discount. DIY stores also sell gas boilers, upvc door sets, consumer units, electric showers etc, which you surely wouldn't expect the incompetent ti fit themselves? Where do you draw the line?