Multisim and Ultiboard

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Initial conditions don't work???

I can't get the "Initial conditions" drop-down to actually do anything. I select "Set to zero" but it doesn't actually set any of the nets to zero. That or the "Initial time step" doesn't work. I have set "Initial time step" to 1e-30 so everything should still be zero when the simulation starts, but it's not. I have attached a project file that shows the problem. It passes a value of 1 through 64 buffers that have a 1ns rise and fall delay but when the simulation starts up, all values are 1. What am I doing wrong?
Thank you for the help.

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Message 1 of 4

There is a docuemnt that shows how to make the initial conditions.


If it is not usefukl please, attache screenshots of the actual issue


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Message 2 of 4

I am aware of the support pages. I would not post here if the support answer worked. The support answer details how to configure individual pieces to have an initial condition. In the simulation settings you select "User Defined" from the initial condition drop-down to use those individual conditions that you configured. However, in the same drop-down as "User Defined" there is also an option that says, "Set to zero". I assume that option is supposed to set the initial condition for all values to zero. That is the option I chose and it does not appear to work. 


I have used the option to set individual things to zero as described in the support pages but it is bugged as well. It works to set the initial condition but it causes the signal to be analog when my circuit is digital and that causes gates to (seemingly) randomly stop working.


I'm not sure what screenshots you want and why that would be better than the actual project file I attached that shows the error but let me know what you want me to show in screenshots and I will provide them.


Thank you

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Message 3 of 4

How do you verify that it is not actually starting from zero? like the simulation of the signal. as you mentioend you are using digital signals, therefore the signal should be a TTL with the rising or falling values. Can you provide that image? How are you simulating? What is the main goal of doing that?

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Message 4 of 4