4 thoughts on “Inhibitor and Reset Arcs in CPN Tools 4”
Thank you for the video.
You mentioned that the inhibitor and Rest arcs cannot be effectively used in the coloured world.
Is there any work around for that?
In a colored model, you can model the concepts by hand. The reason they are not supported is there is no obvious right way to do so in a colored world. What would an inhibitor arc with annotation 1 mans, for example? Would it inhibit with a single token 2 or with two tokens 1? THings only get worse when allowing variables.
What is the inhibitor arc really doing?
I tried again, and sent the unit tokens to the place (via an output arc from one transition), I had an inhibitor arc connected and then another input arc towards another transition
It performed the same thing, even after I removed the Inhibitor arc from the picture. I’m unable to comprehend what the inhibitor arc achieved. Yes, the arc was enabled only as long as there were no tokens on the place, and would disable as soon as any arrived.
But, it’s not doing anything! What would be the purpose?
Is it possible that it’s use is such that it will enable the firing of a transition if and only if the corresponding place is empty.
In that case, another input arc could be attached to the transition (with the inhibitor arc connected to the said place)
and the transition would get fired only as long as this condition is not fulfilled.
What do you think of this take?
Inhibitor arcs can be modeled using colored concepts, so in principle you don’t need them. For various reasons, you may want to use a plain model without colors, and in that case they genuinely add functionality (without inhibitor arcs, Petri nets are monotonic, so adding more tokens can never disable transitions, making them unable to model anything but linear functions).
Thank you for the video.
You mentioned that the inhibitor and Rest arcs cannot be effectively used in the coloured world.
Is there any work around for that?
In a colored model, you can model the concepts by hand. The reason they are not supported is there is no obvious right way to do so in a colored world. What would an inhibitor arc with annotation 1 mans, for example? Would it inhibit with a single token 2 or with two tokens 1? THings only get worse when allowing variables.
What is the inhibitor arc really doing?
I tried again, and sent the unit tokens to the place (via an output arc from one transition), I had an inhibitor arc connected and then another input arc towards another transition
It performed the same thing, even after I removed the Inhibitor arc from the picture. I’m unable to comprehend what the inhibitor arc achieved. Yes, the arc was enabled only as long as there were no tokens on the place, and would disable as soon as any arrived.
But, it’s not doing anything! What would be the purpose?
Is it possible that it’s use is such that it will enable the firing of a transition if and only if the corresponding place is empty.
In that case, another input arc could be attached to the transition (with the inhibitor arc connected to the said place)
and the transition would get fired only as long as this condition is not fulfilled.
What do you think of this take?
Inhibitor arcs can be modeled using colored concepts, so in principle you don’t need them. For various reasons, you may want to use a plain model without colors, and in that case they genuinely add functionality (without inhibitor arcs, Petri nets are monotonic, so adding more tokens can never disable transitions, making them unable to model anything but linear functions).