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  1. #1
    Join Date
    Jul 2002
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    866

    Novar IOM output

    I have a Novar IOM with 2 wires that go to a IMP1010 transducer. I looked at a transducer that is working OK to check the signal going to it but can't figure out what the IOM is sending it. It does flash some resistance when the output light is on but I can't really read it. If I jump the contacts on the IMP it bleeds pressure - so how does it build up pressure? I've tried jumping and manually pulsing the input but nothing. How do I check the signal from the IOM and how do I simulate it at the IMP to check the IMP.
    Second place is the first loser.

  2. #2
    Join Date
    Jan 2003
    Location
    USA
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    1,658
    >I looked at a transducer that is working OK to check the signal going to it but can't figure out what the IOM is sending it


    Most of the outputs are PWM as the IOM/2 has only triac outputs. If it’s PWM the range is like .59-3.59s. There is also what they call multiplexed PWM, which is what that IMP is using. Typically when we swap these out we reprogram the IOM for PWM and use a Kele transducer.

    Your best bet to check operation is use the IOM/2 and in the software force it 0-100%. If the IMP doesn't respond, toss it and do as I describe above.

    As for how exactly the multiplexed PWM works...

    Steady off = de-energizes both valves A & B, ie pressure stays
    Pulsed ON/OFF = Valve A, pressure increase
    Steady ON = Valve B, pressure decrease
    Propagating the formula. http://www.noagendashow.com/

  3. #3
    Join Date
    Jul 2002
    Posts
    866
    There's got to be more to it than just a pulse. The instant I jump the input on the IMP it bleeds all pressure. It wouldn't help holding it for 1-2 seconds when it already bled off. I noticed about 6Kohm from the IOM when it is constantly bleeding. What signal can I send the IMP to check it?
    Second place is the first loser.

  4. #4
    Join Date
    Jul 2002
    Posts
    866
    I have no software and I'm not sure what you mean by valve A & B.
    Second place is the first loser.

  5. #5
    Join Date
    Jan 2003
    Location
    USA
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    1,658
    you got mail
    Propagating the formula. http://www.noagendashow.com/

  6. #6
    Join Date
    Jul 2002
    Posts
    866
    Thanks for the mail O. My issue is this. I can take a UCP622 or UCP822 and jumper the input for a second or two and it will pump up. When I take a working IMP and jumper it the thing begins to bleed the instant I jumper it - but it works when the IOM is wired to it. The IOM must be doing something besides making a pulse contact. I've got a UCP822 I can do manually but when I hook it up to the IOM it doesn't work even though the IOM light is flashing. How can I check the output of the IOM?
    Second place is the first loser.

  7. #7
    Join Date
    Jul 2002
    Posts
    866
    I think the newer IOMs are IOM/2 . THese are older-maybe just IOM.
    Second place is the first loser.

  8. #8
    Join Date
    Jan 2003
    Location
    USA
    Posts
    1,658
    >I take a working IMP and jumper it the thing begins to bleed the instant I jumper it

    If you put a jumper on the input on the IMP, it will bleed air from the branch line as you describe.

    >IOM must be doing something besides making a pulse contact.

    It does three things as described above. Output on (closed contact) = bleeds pressure, pulsed output = increase pressure, and output off (open contact) = no change in pressure.

    You cannot make the UCP work without reprogramming the IOM output for PWM control. IMP was using multiplex PWM which is not compatible with the kele UCPs.

    Once you change the IOM programming for normal PWM, you can setup the UPC for PWM with 0.59-3.59s time base.

    The IOM & IOM/2 use triacs for the outputs so there will be voltage bleed through, when they are off. Easiest way to check them is with a 24v relay or a meter that has a loZ voltage mode..
    Propagating the formula. http://www.noagendashow.com/

  9. #9
    orion242 is right on the money. We do these UCP822 upgrades as the old transducers fail. The relay gives the digital PWM signal the 822 is looking for. Use a good relay as it constantly cycles.

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