Hi folks.

This is the first project I'll work on that will demand a PID control. I'll use S7300 and TIA PORTAL V14 SP1.

Some explanations:

1) The most important variable is TEMPERATURE, so this one must be more stable;

2) I need to control temperature so I thought about using TCONT_CP and QPULSE. It will activate a STEAM valve to increase temperature inside the machine's chamber (the high pressure steam goes inside a serpentine);

3) I also need to control humidity. Can I use TCONT_CP and QPULSE as well? It will also activate a valve, but this one is LOW PRESSURE STEAM directly inside the machine's chamber.

OK. The thing is that the TEMPERATURE AND HUMIDITY must be controlled. And they have influence on each other (for example, the injection of LOW PRESSURE STEAM to increase HUMIDITY will ALSO increase temperature).

How to do this? Could anyone help me? Series association? Parallel association? Could anyone give me an example?

 

Hi folks.

This is the first project I'll work on that will demand a PID control. I'll use S7300 and TIA PORTAL V14 SP1.

Some explanations:

1) The most important variable is TEMPERATURE, so this one must be more stable;

2) I need to control temperature so I thought about using TCONT_CP and QPULSE. It will activate a STEAM valve to increase temperature inside the machine's chamber (the high pressure steam goes inside a serpentine);

3) I also need to control humidity. Can I use TCONT_CP and QPULSE as well? It will also activate a valve, but this one is LOW PRESSURE STEAM directly inside the machine's chamber.

OK. The thing is that the TEMPERATURE AND HUMIDITY must be controlled. And they have influence on each other (for example, the injection of LOW PRESSURE STEAM to increase HUMIDITY will ALSO increase temperature).

How to do this? Could anyone help me with this company airconditionersusa.com? Series association? Parallel association? Could anyone give me an example?

thanks in advance for any help

 

You need to sit down with your process engineer and understand what they are trying to accomplish, together with process data, pipe sizes, fluid properties, and flow rates.

 

You can't control two things at once exactly. What you need to do is have a cost function and minimize that. What error can you tollerate the most or least?