Creating a Closed Loop inside a Control and Simulation Loop

[Peet95]

Hey there,

i am trying to simulate a simple  DC Motor inside a RealTime VI (running an a cRIO9053) I built a few months ago. (VI is attached) Therefore i need to return the rotor speed to multiply it with the back EMF constant. The result will then be subtracted from the input voltage. (as seen in the middle of the block diagram)

A few months ago, with a older version of LabView (2020), the VI ran with no problems. Closed Loops have also not been a problem.

After a PC exchange i installed the latest Version (2020SP1). As soon as i open the VI, all the connections inside the closed loop are dashed and crossed out.

Error: The connection is inside a infite closed loop. (which i actually need)

I also tried to build a simple closed loop control with only a PID Controller, a Transfer Function and the feedback of the output. --> Same Problem.

Can anyone tell me, if this is a problem with the latest LabView version or is there an easy fix in the settings for that issue?

Thanks in advance!

[BertMcMahan]

It opens fine for me with no errors (I didn't try running it, but there are no errors). I suspect you are missing a toolkit.

[Peet95]

Thanks for the quick reply!

Can you show me a list of your installed toolkits so we can compare?

Control Design and Simulation Module is installed.

[BertMcMahan]

I have a bunch but it seems like the Control Design toolkit is the only relevant one. I can say I don't have LabVIEW RT installed

Maybe it's not licensed? Check your NI License manager. Also, try disconnecting and reconnecting a wire to "force" a recompile. See if you can create a very simple loop of some kind without an error.

Also, maybe throw up a screenshot of your error?

I actually haven't used the Control Design and Simulation Toolkit so that's the end of my knowledge here 😕

[Peet95]

Hey,

already tried reconnecting and recompiling. Didn't work..

The product is definitelly licensed. I have access to all Control Design Elements.

I attached a screenshot of the block diagram and the error.

The Error Code is in german. But it basically says that the connection is inside a infinite loop and that the elements can't be executed, because all of them wait for the input signal of one another.

Thanks in advance!