jacek d

  What do you mean by "it is not constant" ? When is it changing ? While you code is running ?

The OP is aiming to create a simulation to test his code. That means the actions of the actuators should reflect on the sensors. The internal memory representing the fill level should change.

@Autogen: In the old days designers wrote additional coding with a mathematical model that simulated the actual environment. Some used Matlab products. Perhaps something like https://factoryio.com/ offer would perhaps work?

Did I understand this thread correctly?

With PLCSim, you can create time-based input changes to see how the PLC logic responds to the changes.  That's part of the simulation system.  Use F1-Help in PLCsim to learn how to use it to meet your specific needs.

If the tank initial volume is always a given value, you can create a DB of "given values", perhaps call the DB "SYSTEM".  In that DB, a tag "TankVolume_initial", and a value of 22.0.

At PLC startup (in OB100), copy SYSTEM.TankVolume_initial to whatever operational tag is used for the "current" tank volume.  Then it can start responding to inputs as stuff flows into and out of the tank at the various controlled rates.

AutoGen_8429407

yes jacked d , i am substracting the initial volume of the tank with the one that someone's asking from the hmi but when code runs the initial value is changing because total volume is reducing.i tried to write the initial value of my tank volume inside a jump but it is not working.No I am not using factory io , simply i dont have the hardware and i am trying with simulation and plc sim to represent a real situation