False Alarms on KNX Sensor

[cristo]

Hello, 
I have a KNX Sensor (GA: 8/0/0) which I have mapped as a Virtual Input.
Sometimes this sensor triggers False Alarms, that I don\'t know how to explain why! (heat waves, maybe).
Is there a way to avoid these false alarms? Is this a known issue with KNX sensors?
Perhaps by programing something like: Only trigger alarm if it detects 3 times in 15 seconds. How can I do this with a Virtual Input?
Thank you.

[ident]

Hi Cristo
KNX sensors may be  more prone to false alarms because their function is more for Presence Detection rather than alarms. Most KNX systems use them for switching on lights. Alarm sensors are designed to minimise false alarms (at least the good ones)

There is a Vibration Analyser Response 86 in the default cclx template which is shown below
If Timer Timer08 = 0 Then
    Do NullResponse After 30 Seconds Using Timer08
    Set Counter007 = 0
End If
Increment Counter007
If Counter Counter007 >= 3 Then
    Stop Timer Timer08
Else
    Skip Alarm
End If

This triggers alarm if there are 3 activations in 30 seconds, you can change the parameters
The Response should be assigned to the Virtual Input.


Alternatively you can use the Alert Zone Type. You need alert zones within 10 minutes to trigger an intruder alarm

[cristo]

Thankyou for the reply.
I tried your sugestion but I think it\'s not working properly. When I arm the alarm, as soon as I apear to the sensor, it starts the entry time countdown (the knx sensor is an entry door). Even if I do a quick apear and hide. 
I assigned the Vibration Analyzer to the On Response of the Zone. Is this right? I also tried the sensivity Zone Type 50 and then 850, but the behaviour was the same.
Am I doing something wrong?

[ident]

The response was not meant to work on an Entry Door zone. It is for an immediate zone that is active when armed


Try this instead
make the zone NOT entry door, but PIR Night/Away instead

Zone Response
If Timer Timer08 = 0 Then
    Do NullResponse After 30 Seconds Using Timer08
    Set Counter007 = 0
End If
Increment Counter007
If Counter Counter007 >= 3 Then
    Stop Timer Timer08
     Start entry Delay
Else
    Skip Alarm
End If


I dont like having a PIR as an entry door. an entry door should be a real  door so that it can be used as the final door arming for away mode.

[cristo]

This KNX sensor is at entrance/exit. I will try later to see if it works.

How do I assign an entry Delay to a normal PIR at an entrance/exit where the keypad is installed? Entry Path?

[ident]

They are different things
Entry Path setting in a zone means the zone will not cause an alarm when there is movement after the entry door is opened for the duration of the entry delay

Entry Delay is the delay started by opening the Entry door when the system is armed. During entry delay the Entry path zones do not cause alarms

[cristo]

Yes, that I understand. My question is:

How do I assign an entry Delay to a normal PIR (because you say one shouldn\'t assign Entry Door to a PIR) at an entrance/exit where the keypad is installed?
(there is no magnet on the fisical \"entry door\". There are only PIR\'s).

[ident]

\"Start entry delay\" assigned to a Pir zone will start an entry delay if it is not an entry doorThat becomes the same as making the Pir an entry door

What I meant is it is better to have a magnetic contact on a door rather than use a PIR as entry door

[cristo]

Ok. So if there are only PIR\'s, the PIR that is nearest to the entry door should be configured as Entry Door, nevertheless, it is a better practice, to have a magnet sensor on the actual entry door, and have it configured as Entry Door. Is this it?

[ident]

nevertheless, it is a better practice, to have a magnet sensor on the actual entry door, and have it configured as Entry Door. Is this it?

That is correct

If you do not have an actual entry door, you have to set the Away Arming Method as \"By Delay\" which means the system will arm to away mode after the fixed delay and you have to give enough time to exit the premises, eg 45 seconds

The system has to wait for that delay before it can arm so to make sure that the system is armed you need to wait for  that time before the system is armed

For \"Away arm by final door\" the system arms a few seconds after the entry door is closed and the exit delay is terminated


if there is an actual Entry door, if the PIR detects motion before the door is  opened when the system is armed, there is an immediate alarm

If there is no entry door and you use a PIR as entry door, then if it detects motion it starts an entry delay, so if there is someone already in the house he gets more time to disable the system

Hence an entry door is more secure and convenient