Pneumatic Noob....
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  1. #1
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    Pneumatic Noob....

    Ok, So I am quite ignorant when it comes to pneumatic controls. Here is the sitrep...

    I am using a Spyder Controller to control some pneumatic actuators using a PWM DO.

    From the Spyder I am running that PWM DO to an ACI EPW. I currently have the EPW's setup with 25.5 on the timing.


    I borrowed the PWM settings from some defaults in Lonspec.

    I currently have these setting on the DO in my Spyder

    Period=25.50
    Zero Time=.10
    Fulltime=25.50

    I am noticing that when/if the PID output goes stagnant like 200 for instance, the air will drop off and the vlv will close. Not good when you need the vlv full bore.


    Help educate a poor ignorant guy, Sally Struthers wants you too.
    Last edited by smokeout; 04-27-2011 at 11:05 AM.
    He who asks a question is a fool for five minutes. He who does not ask any questions is a fool forever.

  2. #2
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    Doesn't sound like a pneumatic problem, sounds like a controller problem, unless you are losing main air to the epw.
    Did you go thru the manual? Look at pg 2 Checkout signal inputs version 2.
    http://workaci.com/sites/default/fil...nstruction.pdf
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  3. #3
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    Yeah, I have everything set right. Using 8-13 and have adjusted accordingly. I agree, seems to be a controller issue. I am not sure on those timing settings.
    He who asks a question is a fool for five minutes. He who does not ask any questions is a fool forever.

  4. #4
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    So what version do you have?

    "Version #2: Solidyne PWM signal and 0 -10 second Duty Cycle Pulse of Barber ColmanTM, RobertshawTM or StaefaTM. No pulse within 10 seconds = minimum output."

  5. #5
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    Version #1. See jumper positions, page 1. Connect the pulse input pos iti ve (+) to the
    down (DN) terminal, and common to the signal common (SC) terminal.
    He who asks a question is a fool for five minutes. He who does not ask any questions is a fool forever.

  6. #6
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    Sorry just wanted to make sure cause ver 2 definitely sounds like the potential issue. I'd give ACI a call if you haven't already.

    Also you made sure your not losing main air, say an EP solenoid valve upstream dropping out? Also is your main air fluctuating at all?

  7. #7
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    No prob at all. Gotta ask.


    Yeah, I have called them. They know the EPW, but the Spyder is different. Good call on Ver. 2 though. I hadn't even put any thought into that option.
    He who asks a question is a fool for five minutes. He who does not ask any questions is a fool forever.

  8. #8
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    Anyone?
    He who asks a question is a fool for five minutes. He who does not ask any questions is a fool forever.

  9. #9
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    A few items:
    - there isn't a spyder tech support # you can call is there?

    - have you tried tying in the feedback signal/monitoring off of the EPW to see what that is doing?

    - Do you have an extra AO available in which you could change this from a PWM to a 0-10/0-5 VDC/4-20 mA signal? Granted you'd need an EPC, but it may be easier at this point.

    I've only worked with a few PWM devices, but I definitely prefer an AO of some sorts whenever possible.

  10. #10
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    Well, I have been tinkering with it just about all day. I think I have found a solution. Seems like if the Pid is full 100 or 200 it jacks it up. I just added a ratio block and limited output to 99. Seems to be responding fine. Can't explain it but, it has been working better like that than it has any other way. Thanks for the help crab.
    He who asks a question is a fool for five minutes. He who does not ask any questions is a fool forever.

  11. #11
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    Can anyone explain the settings? What they actually are?


    Full Time
    Period
    Zero Time

    Think I have a basic understanding, just ain't too terribly sure.
    He who asks a question is a fool for five minutes. He who does not ask any questions is a fool forever.

  12. #12
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    PWM Full - Defines the time period for the Full position pulse. When the on time of the PWM period is at this value the PWM device will position itself to the full position. The minimum resolution of the time value is 0.1 seconds.

    or

    The duration in seconds for the pulse width of a single pulse at 100% output from the control loop. This value must be greater than the value of 0% and less than or equal to the Period value.

    PWM Period - Defines the time period of the PWM signal. This is usually the sum of the Zero time value and the Full Time value. The minimum resolution of the time value is 0.1 seconds. Max time is 3276.7 seconds.

    or

    The duration of a single cycle defined as from the start of one pulse to the start of the next pulse. Must be greater than or equal to the maximum pulse width.

    PWM Zero - Defines the time period for the Zero position pulse. When the on time of the PWM period is at this value the PWM device will position itself to the zero position.

    or

    The duration in seconds for the pulse width of a single pulse at 0% output from the control loop. This value must be less than the value entered for "Full"

    Many PWM-controlled devices cannot provide an output of 0% or 100% because a PWM output shows no switching at these percentages. Therefore, most PWM devices have a minimum duty cycle and a maximum duty cycle between which they operate from zero to full scale. The fields here allow you to configure the full range of settings. It is possible to swap the Zero and Full range values to achieve reverse operation for a PWM output.

    http://en.wikipedia.org/wiki/Pulse-width_modulation

  13. #13
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    Obrigado o meu amigo....


    You heading to Momentum this year?
    He who asks a question is a fool for five minutes. He who does not ask any questions is a fool forever.

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