Results 1 to 17 of 17

Thread: D8 Weirdness

  1. #1
    Junior Member
    Join Date
    Dec 2011
    Location
    Perth, Western Australia
    Posts
    52
    Thanks
    5
    Thanked 1 Time in 1 Post
    Rep Power
    151
    Reputation
    15

    Default D8 Weirdness

    Hi Guys,

    Just set up an external horn for my ness system through the "siren" output.

    Every time my dialler reports - you can hear the dialler through the siren as if it was connected thorough the listen pins?!



Look Here ->
  • #2
    Junior Member
    Join Date
    Oct 2009
    Location
    Melbourne, Australia
    Age
    71
    Posts
    244
    Thanks
    71
    Thanked 90 Times in 56 Posts
    Rep Power
    0
    Reputation
    619

    Default

    Quote Originally Posted by aaronpwa View Post
    Hi Guys,

    Every time my dialler reports - you can hear the dialler through the siren as if it was connected thorough the listen pins?!
    That is called 'Cross-talk' and is common on systems that run sirens constantly, just switching the output on or off.

    Try putting a 3k3 resistor across the siren at the panel, and if that doesn't work, try a 1k resistor.

  • The Following 2 Users Say Thank You to Hound-Dog For This Useful Post:

    aaronpwa (30-04-12),alarmman (01-05-12)

  • #3
    Junior Member
    Join Date
    May 2012
    Posts
    1
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Reputation
    10

    Default

    Hi,

    Make sure the type of siren your using obviously is the corect rated type, from my experiance it sometimes payes to stick with the same manufactured brand for that type of alarm system.
    Noise certainly can be an issue using & eol resistor may filter this out, but might drop the siren output volume down.
    If all fails maybe try wiring the siren directly into the panel to rule out any other issues.

  • #4
    Banned
    watchdog's Avatar
    Join Date
    Jan 2008
    Posts
    2,966
    Thanks
    136
    Thanked 869 Times in 514 Posts
    Rep Power
    0
    Reputation
    8320

    Cool

    From memory the NESS panels have a "listen in" feature. Look through the book

  • #5
    Senior Member
    downunderdan's Avatar
    Join Date
    Sep 2008
    Location
    Sydney Metropolitan
    Posts
    2,497
    Thanks
    163
    Thanked 601 Times in 422 Posts
    Rep Power
    365
    Reputation
    4649

    Smile

    That's an interesting username.

    And you are? :-)

  • #6
    Member
    Join Date
    Oct 2010
    Posts
    333
    Thanks
    14
    Thanked 58 Times in 55 Posts
    Rep Power
    187
    Reputation
    604

    Default

    Hound-Dog is spot on - the outputs on the D8 use open-collector drivers, rather than relays (which provide clean "make" and "break" switching). So sometimes there is a small leakage current, which needs to be shunted with a resistor.

    Quote Originally Posted by DigiNess View Post
    Make sure the type of siren your using obviously is the corect rated type, from my experiance it sometimes payes to stick with the same manufactured brand for that type of alarm system.
    Shouldn't matter what brand of horn speaker you use, as long it is 8 ohm and its power rating is within the manufacturers' specifications. (unless you work for the panel manufacturer, of course).


    Quote Originally Posted by DigiNess View Post
    using & eol resistor may filter this out, but might drop the siren output volume down.
    Are you sure about this? Put a 1k or 3k3 resistor in series with a horn speaker and hear how much sound you get out of it. The shunting resistor, by definition, always goes in parallel.

  • #7
    Banned
    watchdog's Avatar
    Join Date
    Jan 2008
    Posts
    2,966
    Thanks
    136
    Thanked 869 Times in 514 Posts
    Rep Power
    0
    Reputation
    8320

    Cool

    Quote Originally Posted by Hound-Dog View Post
    That is called 'Cross-talk' and is common on systems that run sirens constantly, just switching the output on or off.

    .
    What is that supposed to mean?

    Hound-Dog is spot on - the outputs on the D8 use open-collector drivers, rather than relays (which provide clean "make" and "break" switching). So sometimes there is a small leakage current, which needs to be shunted with a resistor.

    Alarmman - If you have leakage at an open collector output then it is stuffed. It is OPEN collector not LEAKY collector. You may be thinking of the supervision current that is there by design.

  • #8
    Member
    Join Date
    Oct 2010
    Posts
    333
    Thanks
    14
    Thanked 58 Times in 55 Posts
    Rep Power
    187
    Reputation
    604

    Default

    There are plenty of explanations on the internet about how an open-collector output works. Here is just one of them:

    On an alarm panel, with an audio load (say a horn speaker, screamer etc) connected between the positive supply and the open-collector output, in theory when the output is off, there is no sound. However, sometimes there is a small voltage present on the output due to leakage currents in the internal circuitry controlling the output. This voltage is sometimes enough to cause a soft sound to be emitted from the sounding device. I've had this happen many times when connecting screamers to open-collector outputs on the Solution panels. A 1k to 3k3 resistor between the output and COM+ always fixes the problem. In fact, in this situation I now fit a resistor across the output as standard.
    Last edited by alarmman; 02-05-12 at 07:14 AM.

  • #9
    Banned
    watchdog's Avatar
    Join Date
    Jan 2008
    Posts
    2,966
    Thanks
    136
    Thanked 869 Times in 514 Posts
    Rep Power
    0
    Reputation
    8320

    Cool

    Great reference , a blog for builders. Get a load of this bit of rubbish they state -

    "Here’s an example…when the transistor is off, and you have one lead of a resistor on the collector and the other lead tied to 12 VDC"

    It doesn't seem to be important that they tell you the resistor they mention is in fact your switched load.

    Maybe you should check electronic texts references.
    I will say once again - if you have un designed leakage current at the collector then you have a fault condition or shithouse design

    If you continue to put peizos on outputs that are not designed for them , you will continue to have that problem
    Last edited by watchdog; 02-05-12 at 08:39 AM.

  • #10
    Member
    Join Date
    Oct 2010
    Posts
    333
    Thanks
    14
    Thanked 58 Times in 55 Posts
    Rep Power
    187
    Reputation
    604

    Default

    Not interested in arguing the point with you. I know and understand the theory, and am only stating what I experience in the "real world". Next time you have ANY type of load connected to an open-collector output, measure the voltage across the output whilst it is switched off, and see what reading you get.

    If you can't connect devices such as piezos directly to open-collector alarm outputs, then what do you suggest I do? (I know the answer, just seeing if you do).

  • #11
    Junior Member
    Join Date
    May 2012
    Posts
    2
    Thanks
    0
    Thanked 1 Time in 1 Post
    Rep Power
    0
    Reputation
    15

    Default

    bla bla bla too much politics.... I say replace the board and be done with it!

  • #12
    Banned
    watchdog's Avatar
    Join Date
    Jan 2008
    Posts
    2,966
    Thanks
    136
    Thanked 869 Times in 514 Posts
    Rep Power
    0
    Reputation
    8320

    Cool

    Quote Originally Posted by alarmman View Post
    I've had this happen many times when connecting screamers to open-collector outputs on the Solution panels. A 1k to 3k3 resistor between the output and COM+ always fixes the problem. In fact, in this situation I now fit a resistor across the output as standard.
    I need to ask what output do you connect your screamer to. Bosch designate O/P 4 (relay) as the screamer o/p & as you have found out , they probably do that for a reason. Why not try using it ?

    Here's a project for you. Grab yourdelf a switching transistor (BC547 etc) Put your multimeter (on ohms) across the emitter & base & measure. Reverse the leads & measure again. Divide 12 by the answer you got in ohms & you end up with the leakage current. If it has been designed as a switching circuit then the biasing will be set up to drive it into saturation. With proper design techniques, in the "off" state there will be no collector/emmitter leakage

  • #13
    Junior Member
    Join Date
    Dec 2011
    Location
    Perth, Western Australia
    Posts
    52
    Thanks
    5
    Thanked 1 Time in 1 Post
    Rep Power
    151
    Reputation
    15

    Default

    Hi

    - This is the Ness brand Horn
    - This is connected directly with the fry leads of the siren to the "siren" output
    - Yes, the listen PINS are at the top of the PCB ... seperate.

    I will try some resistors later in the week and report back.

    Thanks Guys.

  • #14
    Member
    Join Date
    Oct 2010
    Posts
    333
    Thanks
    14
    Thanked 58 Times in 55 Posts
    Rep Power
    187
    Reputation
    604

    Default

    Quote Originally Posted by watchdog View Post
    I need to ask what output do you connect your screamer to. Bosch designate O/P 4 (relay) as the screamer o/p
    One application (of many) that I use the other outputs for: I set up partitioning properly, unlike nearly every other alarm company out there.

  • #15
    Banned
    watchdog's Avatar
    Join Date
    Jan 2008
    Posts
    2,966
    Thanks
    136
    Thanked 869 Times in 514 Posts
    Rep Power
    0
    Reputation
    8320

    Cool

    Quote Originally Posted by alarmman View Post
    One application (of many) that I use the other outputs for: I set up partitioning properly, unlike nearly every other alarm company out there.
    I'm not sure how its possible to set up partitioning improperly. Anyway , enough bickering the OP said he could hear the DIALLER through the HORN. Screamers never came into it.

  • #16
    Junior Member
    Join Date
    May 2011
    Location
    Melbourne
    Posts
    34
    Thanks
    8
    Thanked 0 Times in 0 Posts
    Rep Power
    158
    Reputation
    10

    Default

    This may be of some help to you.

    P89E 3E - Listen In To Dialler.

    This is a diagnostic feature to allow the installer to hear the dialler message and other
    telephone tones through a horn speaker.
    There are 2 methods of listening to the dialler.
    Method 1: Temporarily connect a horn speaker to the LISTEN pins on the main
    board. This method required no programming options to be set - the LISTEN pins are
    always active.
    Method 2: This method requires option P89E 3E to be turned on. Listen-In is enabled
    for a minimum of 4 minutes after exiting Program Mode.
    During Method 2 Listen-In, the dialler message and other telephone tones can be
    heard through the Siren output (at low volume) while the dialler is sending reports. The
    4 minute period is restarted whenever any key on the keypad is pressed.
    To turn Listen-In off, go back into Installer Program mode and toggle the option OFF.

  • #17
    Banned
    watchdog's Avatar
    Join Date
    Jan 2008
    Posts
    2,966
    Thanks
    136
    Thanked 869 Times in 514 Posts
    Rep Power
    0
    Reputation
    8320

    Cool

    Thanks Dean , I mentioned that in post #4

  • Bookmarks

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •