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Alarm Control Panel

hmlittle59hmlittle59 Posts: 404
in General Discussion
Hello All,
Has anyone ever integrated a (Carbon Monoxide/Fire) detector to a "Alarm Control Panel" and know how the work or designed your own Custom Control Panel? I've purchased the CM-E1 CO detector and I'm learning the ins and outs of the units connection. Want to be sure an capture all errors and any other things to look out for when making my own "Custom Controller".

Thanks for any knowledge or insight.
Note: I've got a lot of "google"/Douglas Krantz printouts to get me started.

Howard

Comments

  • DigitalBobDigitalBob Posts: 1,513
    I' m not an alarm guy but I see a loop with three states. The normal state runs through a resistor giving a steady voltage or current level. A fault would give an open state no current or voltage. An alarm state would give you a high current or high voltage level. I don' t build alarms but I'm guessing that would be a plausible scenario .
  • kwinnkwinn Posts: 8,697
    The CM-E1 CO detector needs a 12V or 24V power supply to operate and has two dry contact relays. The connection diagram is on the attached data sheet. Wired as shown the alarm panel can detect three conditions (normal, alarm, trouble) based on the current draw of the circuit. This is a typical connection for sensors to an alarm system.

    Sorry, could not attach the data sheet, it was too big. You can download it by googling "CM-E1 CO detector".
  • DigitalBobDigitalBob Posts: 1,513
    Fire alarms run in a loop class A , Class B. The end of the loop is terminated with a 4.7K resistor for 24v systems. Ref. NFPA 72 looks like my guesstimate logic was really close.
  • hmlittle59hmlittle59 Posts: 404
    Thanks for the Feedback guys.

    I have all the printouts and then SOME from the CO gas detector, but I'm trying to make sure I fully understand the errors and how they are distinguished (1,2, and 3 with only 2 lines) on the Control Panel and the Circuitry involved. MY pcb already detects open/closed magnetic switch(s), so that part I understand, its the 3rd error that I'm trying to fully understand and make sure that I can detect it or figure out some other way. I do have an extra I/O pin, (Active Low) that maybe I can incorporate.

    I have the Parallax (10k/220 ohm) on my I/O pins...This has worked great in the pass and I even have my own Custom switch board (5 keys...up/down/right/left/select) through a MainMenu on Serial and/or Parallel LCD Screen. Just trying to figure in that 3rd error with only (2) two lines. Just hasn't clicked in my mind yet on how to do it.

    The CO is something I want to add on. The new PCB's should arrive here by this Saturday and the current layout will detect at lease 2 states.

    Hope this gives a clearer insight on my dilemma.

    Note: I saw a cheap Control Panel on Ebay ($24.00) that may have the schematic with it that maybe I can learn from.

    I did get some Control Panel printout from good ole "Google", mainly "Fire" connection and errors.

    Thanks for any help.
  • DigitalBobDigitalBob Posts: 1,513
    You could use a mcp3208 ADC. Then use a 24vdc supply to send out the voltage thru the loop (class B system) and terminating resistor. And route the return to the MCP3208 thru a voltage divider. Program the prop chip to read the voltage for all three states. Then output an alarm for each one via output pin.
  • hmlittle59hmlittle59 Posts: 404
    I'm using the PBASIC48W_P40 and "ALL" pins are being used. I have not use the ADC chip before. Maybe....the last two pins can be released for the ADC chip or if the DS1302 can share some of the same lines plus the 2 I/O pins. I will look into that approach also. Not much if any code space left in any of the 8 Slots.

    Thanks.

    Still looking on Ebay for that cheap Control Panel that I saw two nights ago...

    Thanks again.
  • kwinnkwinn Posts: 8,697
    The sensing can be done with two I/O pins if you used a dual comparator to sense the voltage from the CO detector.
  • hmlittle59hmlittle59 Posts: 404
    edited 2017-04-23 23:57
    UPDATE:

    Hello ALL,

    After reading the Manual of the unit I purchased and other web. Printouts and various Control Panel manuals...over and over and over again, along with wiring connection, I think that I understand how it works and can now re-re-reorder my OWN PCB and make it work.
    That's without seeing a schematic of an actual Fire/Gas "Alarm Control Panel".

    My PCB's coming in this week will work as is, but future boards will need a Supervisor Circuit (Loop). Part of the Loop will consist of the 10 k of the (10 K/ 220 ohm) Pull-up resistor combo moved to be the Supervisor Circuit. Meaning, 5 vdc from my PCB will go out and Loop through the 10 K End Of Line Resistor (EOLR) and come back to my PCB and then through the 220 ohm resistor and to the sensing I/O pin.

    Now, Just trying to figure if I need a dedicated 'Common' pin per I/O pin or split one (1) per 2 I/O pins. Four (4) I/O's and two (2) Commons. I don't thinks so off the top of my head for now.

    Thanks for any input

    EDITED...Sorry for not proof reading, was running out the door to visit someone in the Hospital.
  • hmlittle59hmlittle59 Posts: 404
    UPDATE(2):

    In my hast, I did a simple over site about connecting the returning END(s) of 2 Supervisor Circuits to a Common connection.
    WRONG WRONG WRONG.
    This would connect one I/O to another I/O and during Alarm or Trouble could cause 2 or more I/O pins to go into Alarm at the same time.
    OOPs...
    Will Cut and Hack on the new new boards coming in to make this work and then re-spin.
  • kwinnkwinn Posts: 8,697
    hmlittle59 wrote: »
    UPDATE:

    Hello ALL,

    After reading the Manual of the unit I purchased and other web. Printouts and various Control Panel manuals...over and over and over again, along with wiring connection, I think that I understand how it works and can now re-re-reorder my OWN PCB and make it work.
    That's without seeing a schematic of an actual Fire/Gas "Alarm Control Panel".

    My PCB's coming in this week will work as is, but future boards will need a Supervisor Circuit (Loop). Part of the Loop will consist of the 10 k of the (10 K/ 220 ohm) Pull-up resistor combo moved to be the Supervisor Circuit. Meaning, 5 vdc from my PCB will go out and Loop through the 10 K End Of Line Resistor (EOLR) and come back to my PCB and then through the 220 ohm resistor and to the sensing I/O pin.

    Now, Just trying to figure if I need a dedicated 'Common' pin per I/O pin or split one (1) per 2 I/O pins. Four (4) I/O's and two (2) Commons. I don't thinks so off the top of my head for now.

    Thanks for any input

    EDITED...Sorry for not proof reading, was running out the door to visit someone in the Hospital.

    You don't need a dedicated common per I/O pin. All the I/O pins can share a single common, although the typical setup is one common connected between two I/O's.
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