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Brand new to PID first time productivity user

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  • Brand new to PID first time productivity user

    Well here I go I have the following p2-550 cpu a p2 08 ADL-1 ANALOG INPUT CARD a p2 04DAL-1 Output card. I created a pid named heating vessel
    set point tag is at 120 vessel_temp is at 81 that's my PV input range max is 100,input range min is 0,proportional gain set at 10,intergral set at 3,deriv didn`t use, Analog output is a 1 I think I have programing issue here,Output range max 100,output range min 0,

    I scaled my analog input to get real temp number how do I do that with the analog output? I don`t understand why its a 1 I was expecting

    Any help greatly needed and very much appreciated. The quicker the better

  • #2
    The Process Output is a numerical value and is scaled into the Output Range Max and Output Range Min.
    The Output Upper Limit and Output Lower Limit can be used to clamp the output to a value inside the Range scaled window.


    • #3
      Roger thanks I have been struggling with this all week. Finally I have a working PID loop. It turned out I had the upper limit set to 100 which I thought was 100 percent of out put but actually I needed it set to the upper limit of the analog output card which was 4095. I kept reading your post and finally. But thanks. Now can I use the ramp function with the PID output as well? They want to ramp to temp 3 degrees a minute or something to that effect. I`m so thankful for the assistance I`ve gotten here on the forum. Our project engineer left so I have been trying to fill some big shoes really I`m just trying to learn and get better at plc`s thanks everyone. Turns out I have done really well with all the help I have gotten here


      • #4
        The Ramp Soak is used on the Setpoint to change it over time.
        The PID loop will take care of the output just as if you had manually changed the setpoint in small amounts.

        The example in the help file is pretty good. Try it on a loop that can be monitored to test.