# SIM: States Pane

The States Pane contains three tabs.

### Current State Tuple

This tab displays all the DES that are being simulated and what their current states are, that is, the current states at the current step. They are listed in a hierarchical form for easier viewing. The DES names are listed followed by their current state. The next two columns indicate whether the current state is an Initial state and whether it is a marked state. The last column indicates if the DES Viewer is open or not for that DES. Double-clicking on a DES will open a Graphical Viewer for that DES, if the DES contains graphical information (i.e. The DES has been edited in the Graphical DES Editor). As the simulation proceeds, the viewer will update.

### Next State Tuple

This tab is enabled when in History View or when an event is selected in the Eligible Events tab. When stepping back through a simulation, the Next State Tuple displays all the DES and their states they will change to when the next event occurs. This is only available in History View because the event has already taken place so we know what the Next State Tuple will be. As with the Current State Tuple tab, the Next State Tuple tab displays all the DES in a hierarchical form, followed by their next state, based on the event that has already occurred, and the Initial and Marked properties of that state.

### Trace

The Trace is a quick way to follow a simulation in a textual form. It first lists all the information related to the simulation including information such as event set and stop condition. When simulating, it lists first the step number, then the previous state tuple, the eligible events, the event chosen and lastly the current state tuple. When listing the state tuples, you may notice that sometimes it displays all the DES names followed by their states and sometimes it only lists states. This is a shorthand feature of the trace to make it easier to read. To change the Frequency to show DES names and for other simulation options please see the Dashboard tab of the Events Pane. For example, if the frequency is set to 1, the DES names will display every time. If it is set to 4, it will only display the DES names every fourth step. You will also notice when running a long simulation that the trace will appear to reset after a number of steps. This happens when the Frequency to flush trace to disk count has been met. To save memory and space, the trace is written to a file and cleared from the window at a user defined interval. This frequency can also be changed in the Dashboard tab. To read the state tuples a shorthand is used to save space. Here is a sample trace.

As you can see this is the first step in the simulation (Step=1). The first thing displayed in the Previous State is [I][M]. This indicates all the DES are at Initial and Marked states. Next is the DES names. Preceding each DES name there is a ^ and a * symbol. The ^ indicates the DES is at an Initial state. The * indicates the DES is at a Marked state. Next is the DES name followed by a / and the state name. This information is then separated by a comma , and repeated for each DES. The next image shows the trace without the DES names.

As you can see, the same information is present except for the DES names. Notice that the [I] and [M] are not shown. This is because at least one DES is not at an Initial or Marked state. In this case, the last DES. At this state tuple two events are eligible. The event chosen is 'package' which causes the last DES to to change states. You can see this because all the states are the same from the previous state to the current state except for the last DES.

Clicking on the Trace Viewer button brings up a text editor allowing the entire trace to be viewed at once.

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