3 way Control Valve from Siemens with Beckhoff PLC

tech007
2011-04-06
2018-06-15
  • tech007

    tech007 - 2011-04-06

    Hello,

    I have question regarding the 3 way control valve with magnetic actuator which is MXG461B15-1.5. As i want to use this valve for accurate water temeprature control application for cold and hot water. I would like to control the outlet temperature of the water. I have gone through the documentation of this control valve also.

    This valve input and output, i will connect with Beckhoff PLC Terminals
    respectivaly EL3162 and EL4104.

    Now, there are three different ways for controlling through the switch position.

    1. Voltage control
    2. Current control
    3. As per valve characterisitc i.e. Linear and Equal Volumetric %

    My question is, how to control from the PLC ? Do i need to change the
    voltage or current respectively from terminal ? From where i should get feedback of position
    or position error ?

    I have limitation also that i can use only Beckhoff PLC as another system running
    on Beckhoff PLC.

    Can i get example with same terminal from Beckhoff i.e. EL3162 and
    EL4104 ?

    Thanks.

    Regards,
    tech007

     
  • shooter

    shooter - 2011-04-18

    as you have a voltage output on your plc set the valve to this (better would be a mA signal ) but use what you have it will work.
    the valve should also be in voltage control, As the feedback has the same configuration it is impossible to use the feedback (not needed anyway as the valve will not be stuck anyway).

    For character i first would use linear and if valve tends to regulate in lower or higher 20% ( below 20% or above 80% change over to exp.) this way you have better control of the temp.

    Now use two temp sensors one in your tank and one on the outgoing line this will gaurantee you never go out of bounds and you can control your tank accurate.

    for a good PID or control look at w www.oscat.de w
    if you would like it fuzzy (expert system ) give me mail.

     
  • tech007

    tech007 - 2011-05-11

    Hi,

    I will go with voltage 0-10 v feedback signal. And as per chearacterisitc concern, as you said i will try first

    with linear. And then, try to maintain the temperature on inlet and outlet pipes.

    I am planning to use three sensor. One with hot water pipe and second with cold water pipe. At the outlet of
    valve, i willalso measure with temperature sensor. So, i can really have good idea of valve controlling

    behaviour.

    I am planning to use PID controller. I need to try it out that.

    I learnt fuzzy logic but i didn't touch it since 3 years.

    I will send you email once i decide to use fuzzy logic.

    Thanks.

     
  • shooter

    shooter - 2011-05-11

    you do not need the feedback so yes i would use 0-10 Volt too.
    As this is your output card doing.
    the siemens valve can only do one type it is 4/20 mA OR 0/10 V.

     
  • tech007

    tech007 - 2011-05-23

    Hello,

    I using beckhoff terminal EK1100,EL3162(analog input) and EL4104(analog output). The application is to control the valve thorugh

    analog input and output terminal. But right now, i want to programme analog terminals.

    I am giving additional 10 V DC to analog output terminal and measuring at analog input terminal through multimeter.

    I would like to have similar voltage 10 V DC at input terminal which i am giving at analog output terminal 10V DC.

    My problem is at analog input terminal i am getting variable DC voltage although i am giving contast dc voltage to analog output

    terminal. And this varibale voltage is keep decreasing and reachign zero at analog input terminal which i want to measure.

    There is no error as well. All terminals in OP mode.

    For programme, i am using FB which is analog_in and analog_output and variables linked through respective input and output.

    Can somebody help me with this ?

    Can i have example programme for Twin CAT system ?

    Thanks.

     
  • shooter

    shooter - 2011-05-23

    VAR
    a AT %QW0 :INT;
    output :INT:=20000;

    END_VAR

    program
    a:=output

    start by login
    and run the program
    duobleclick on output
    change the value and press F7
    this is smallest test possible.

    see my previous post.
    about type of outputs and inputs.
    I also use these siemens valves for expansion valve in freezing installations.

     
  • awaisyaqoob

    awaisyaqoob - 2018-06-11

    hello. i need help connecting beckhoff plc with codesys.

     
  • eschwellinger

    eschwellinger - 2018-06-15

    Hi,
    what about using an EL6692 to connect both ethercat masters?
    Which plc are you using on CODESYS side.

    BR
    Edwin

     

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