The point at which a transition enters a submachine

Indicates the default starting state at a level of nesting within a state contextĪ kind of junction connector in which at most one of a number of exiting transitions is selected based on the evaluation of guard conditions The notation for deep history is the same as for shallow history, with an additional asterisk (*) behind the “H.” More specifically, when you switch it on again, the hairdryer jumps into the state configuration low and hot/extreme. However, when using deep history, the device also restores the substates in the configuration that was active last. Within this state, the substate normal is activated since the initial state points to it. Using shallow history, when you switch it on again, the device sets itself to the state hot, as described above. This means that the hairdryer will immediately jump into the low and hot/normal configuration after the second time you use it.Īs the name implies, deep history has a “deeper” effect than shallow history. When you now switch the hairdryer on a second time, when traversing the shallow history, the device will read the state that was last active and activate it directly. Shallow history causes the substate of the pertaining region that was last active to be saved. We'll now have a closer look at the circle symbol with the “H.” This is the notation for shallow history. This situation can be improved, at least in the model, by using history states. After the third, fourth, or fifth time you do this, you might come to think that this hairdryer is not fit for everyday use. So again, you have to go through the hassle of resetting it to high and hot. The next time you use the hairdryer it will come on in the default state configuration- low and cold.

Datastage 7.5 architecture diagram