newbie help on wired or wireless pirs

[JohnD]

I have never denied that other transmissions can occur. I have never said that other transmissions come only from othe Yale devices. The source of interference is irrelevant.

However, I have repeatedly said that the in an ordinary domestic house, in an ordinary residential street, the probability of an interfering signal blocking a sensor, at the exact fraction of a second that a burglar breaks into your home, is extremely small, and I have repeatedly asked you to give your estimate of the probability, which you refuse to do. You have also failed to provide evidence it.

The only thing that actually matters, is, in an ordinary domestic house, in an ordinary residential street, the probability of an interfering signal blocking a sensor, at the exact fraction of a second that a burglar breaks into your home.

The rest is just fanciful speculation.

 

[bernardgreen]

Hey as Bernard will tell you you can never predict how a system will work until you have it actually in place in the environment it will be in .

You CAN make a fairly accurate prediction by doing a radio survey of the site BEFORE commiting to purchase.

Of course the survey results are valid only for the period of the survey and there could be a significant change in channel usage the day after the survey has been completed.

Read more: //www.diynot.com/forums/alarms...-cost-diy.313197/page-3#2628641#ixzz2ROBDihEa

So John, either commission a survey to obtain channel occupancy information and then you can work out the percentage of messages from sensors that will not reach the panel. Or collate information about what other equipment is being used in the area and then using the data on TX power and duty cycle of each transmitter calculate the channel occupancy.

Now please stop mis-leading people into believing that an alarm system that depends on one way communication on a licence exempt channel will never suffer loss of packets.

 

[JohnD]

really, Bernard, you should know better than to fib like that.

Show me where I have said "never" and I will send you £5.




You are the one making unsubstantiated allegations and issuing dark but vague warnings. When you are ready to estimate the probability that, in an ordinary domestic house in an ordinary residential road, interference will block a sensor at the same fraction of a second that a burglar breaks into your home, come back. You and I both know the probability is vanishingly small.



p.s.

You might benefit from reading this
http://en.wikipedia.org/wiki/Anecdotal_evidence

Always happy to help.

 

[mdf290]

Now please stop mis-leading people into believing that an alarm system that depends on one way communication on a licence exempt channel will never suffer loss of packets.

I can't believe you are still banging THIS particular drum Bernard.

What if it suffers a lost packet? The pirs dont just report movement once. They send repeatedly?


Here's a few more WIRED ALARM 'What ifs' for you Bernard.

All relating to professionally installed wired alarms whereby the result is that the alarm did not have the necessary result.

WHAT IF?

The electricity is off for more than 10 hours
result - alarm will not work

The Phone Line is damaged or cut.
result - The monitoring station cannot request Police Response

The burglar breaks in through a window
result - The door contact will be bypassed and the alarm wont activate

The professional installers don't do a proper survey
result - Their may be unprotected areas vunerable to burglary without activating the alarm

The user fails to set the alarm
result - It won't go off

The criminals perform a smash and grab
result - The alarm will activate but IT WILL NOT PREVENT the burglary

The alarm activates but is ignored by the neighbours
result - what was the point of installing it.



But here is the biggest what if Bernard.

What if someone repeatedly scaremongers about a 'particular' alarm system which is the only system within the budget of a particular sector of the community?

Result . . Instead of installing another type of system which they CANNOT AFFORD they may decide it is not worth fitting any alarm at all.

. . This is a serious effect of the continued negative spoutings of someone deliberately trying to dissuade people from fitting a particular system because . . .

95% of an alarms job is done by the box on the wall. That box on the wall is the major reason the alarm was fitted in the first instance.
85% of burglars surveyed avoid alarmed homes.

The spoutings relating to the system in question are disengenious because they DO NOT ALSO MENTION that there is NO SUCH THING as a guaranteed police response or that WIRED sytems can ALSO fail.

There is just an extremely simplistic inference that the wireless systems are unreliable and may not work when you need them.

However this information is supplied by someone who despite his technical background HAS NEVER HAD A YALE ALARM AND HAS NEVER USED ONE AND CANNOT SAY HOW IT WOULD OPERATE IN HIS OWN HOME.

 

[bernardgreen]

What if it suffers a lost packet? The pirs dont just report movement once. They send repeatedly?

Do they ? You have said they send a motion detected and then go to sleep until a minute without movement has passed, then they wake up again. Yale Technical confirn this. ( you were told the name of the person at Yale who confirmed this to me )

So now you try to find fault with wired alarms, all of them apply equally to wireless alarms

The electricity is off for more than 10 hours
result - alarm will not work

Applies to all alarms

Cut phone wires ? A good alarm that relies on phone line does not have the line run where it can be cut. A monitored alarm often has the critical line monitored and cutting it will create an alarm at the monitor station.

The professional installers don't do a proper survey
result - Their may be unprotected areas vunerable to burglary without activating the alarm

Some "professional" installers may not do a full survey, but most do, some who install wireless linked sensors have the necessary test equipment for verifying signal strength and other critical parameters are aceptable. And those the sensors on that quality of system do not send once and then go to sleep but continuously repeat alarm messages until they receive confirmation from the panel that their alarm has been received. Not possible on one way licence exempt channels.

The alarm activates but is ignored by the neighbours result - what was the point of installing it.

You know the connection between this and the link that prevents the alarm sounding when jamming occurs. The same does NOT apply to wired alarms which cannot be made to false alarm from outside the property simply in order to make the owner turn off the jamming detected alarms.

However this information is supplied by someone who despite his technical background HAS NEVER HAD A YALE ALARM AND HAS NEVER USED ONE AND CANNOT SAY HOW IT WOULD OPERATE IN HIS OWN HOME.

And you promote DIY alarms because you sell them and then charge for installing them. Hence you have a vested interest in them.

Yet over the past year you have been surprised to learn some very basic knowledge about how they work. ( like the fact that they do not send regular "I am OK" transmissions which means the sudden death of a sensor is nor detected by the panel )

I can say that in my home it is likely that the jamming detection on a Yale alarm would have to be turned off to prevent my neighbours being disturbed by "false" alarms. These alarms would be caused by legal transmissions on the channel from nearby properties found by using an off air monitor ( as a professional installer of radio systems you will know about these ).

The public domain information and freely given information from Yale Technical supports my profession opinion about alarms that use one way communication on licence exempt frequencies.

In an ideal environment they will work but if one wishes to rely on them continuing to work when needed then one has to ensure that ideal enironment is maintained. Because the radio channel is licence exempt there is no recourse if a neighbour starts using the same channel. The only time action could be taken is when a criminal uses a transmitter to block the systems in a street but even then there is the need to prove intent to commit a criminal act.

 

[bernardgreen]

You might benefit from reading this
http://en.wikipedia.org/wiki/Anecdotal_evidence[/QUOTE]

Unlike anecdotal evidence, the reliability of accounts of personal experience is normally capable of assessment for legal proceedings.

Make that personal professional experience where I have been involved in post incident assessments. ( AKA investigating what went wrong )

 

[JohnD]

really, Bernard, you should know better than to fib like that.

Show me where I have said "never" and I will send you £5.

Still waiting.

 

[bernardgreen]

You said vanishly small. To many people that equates for all practical purposes as zero.

Keep your fiver, I have a more than adequate pension.

 

[JohnD]

really, Bernard, you should know better than to fib like that.

Show me where I have said "never" and I will send you £5.

Still waiting.

It appears Bernard can't quite admit that he was fibbing.