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LabVIEW Information

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    LabVIEW 2015
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Shleeva's Achievements


Newbie (1/14)



  1. Yes, the blue arrows do outline the cycle. I put a Feedback Node in the red rectangle and wired 0 to the Initializer Terminal and the cycle error got fixed so I was able to run the VI, but the graph wouldn't even move forward, so it doesn't work properly. And when I put an additional Feedback Node in the green box with 0 wired to the Initializer Terminal, I got a new error (sorry but somehow I can't post the screenshot, so a quote will have to do): and the "Show Error" button just points to the whole Simulation Loop. Maybe I should put a different value for the Initializer Terminal?
  2. They make do, although they can put a massive strain on the processor - in my other model, where I have to calculate the position of a pendulum driven by a DC motor and then visualize it, there are some sine and cosine functions to compute and my computer has a hard time doing the calculations in real time. There are other solvers, like SDIRK 4, which can speed it up a bit, but it's still a big hassle for the processor and I'm forced to set the simulation timestep pretty high (like 0,1 s) so that it eases some burden but makes the simulation and visualization choppy. I've already tried this workaround, and unfortunately the results where nowhere near what they should've been. Unfortunately these settings are only for configuring the simulation parameters which determine the way the simulation is run, like the solver of choice and the time step, or timing settings which allow you to synchronize the simulation with a specific source to make the simulation run at a desired speed.
  3. I don't need to really solve anything myself, because the Simulation loop in LabView has built-in ODE solvers (like Runge-Kutta) for different equation orders, and can include a fixed or a variable time step. That's what I tried doing next, and it did allow me to solve for φ, but it returns some weird values. And I also need to solve for x somehow, and it repeats the error in φ. I think that this is might actually be the core of the problem here. The initial conditions for x and φ should both be 0, but I just don't know how to set them in this loop.
  4. Yes, the messages, as I said in the thread title, are saying this: The details are exactly the same for all messages. I know I probably need some feedback nodes, or something else with indirect feedthrough, but I don't know where to put it and how to configure it. I'm still pretty new to LabView, modeling and simulation.
  5. As I stated, I know the reason why the wires are broken, I just don't know what to do to fix them. Viewing the Error List won't help much, because it just tells me that the parts of the diagram are interdependent, but doesn't say what to do specifically to fix it.
  6. Hello. This is my first post here, so I apologize in advance if an answer to my problem has already been provided somewhere. I have to model and simulate a gantry crane in LabView for my engineer's thesis. The draft looks like this: Here are the final equations for the model: Since I'm not really big on all the modeling stuff like transfer functions etc. I used the simplest way I know to model this - by using summation, gain, multiplication and integrator blocks in a simulation loop and then wiring all the necessary parameters. However, I stumbled upon a problem after finishing the wires... (Sorry in advance if it looks a little messy) So, all the broken wires are a part of a cycle and I can't run the simulation. I know that this is due to the fact that the second derivative of x is dependent on the second derivative of phi while the second derivative of phi is also dependent on the second derivative of x, and I know it all has something to do with Direct Feedthrough and I need to make it into Indirect Feedthrough using a function which has Indirect Feedthrough in it, but I don't quite understand how to utilize it here. Could anyone please lend me a hand here? I'd really appreciate a fast and simple answer, since I'm kind of short on time for this.
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