# Status Indicator

The status indicator is an Interface layer object that you can use to provide information about the status of key outputs in your simulation model. You can configure a status indicator to display as a simple lamp, or as a speedometer-type gauge. In either case, the indicator will light up using green, yellow, or a flashing red color to indicate the status of the key output. As you create the status indicator, you can set a range of values for green, yellow, or red display. Status Indicators thus are an excellent mechanism for telling users of your models the status of the system at a glance.

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Surface Operations

To create a Status Indicator, click once to select the icon from the object palette. Move the cursor to the desired location on the interface layer, and click to deposit the device. Double-click on the object to enter its define dialog. The default dialog looks something like what you see in Figure 6-73.

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Dialog Operations

Within the dialog, there are three basic tasks. First, you need to determine whether to display the indicator as a lamp, or as a speedometer.. Second, you need to assign a variable to the indicator Finally, you need to configure the device.

Figure 6-73 Status Indicator Dialog Box

Lamp vs. Speedometer Display: Within the dialog, your first decision is whether to display the indicator as a lamp or as a speedometer gauge. The default display option for the status indicator is a lamp. The lamp indicator will be displayed as a smallish circle. The lamp will use color only -- green, yellow, or flashing red -- to report out the status of the assigned variable. If you uncheck the "Show as Lamp" checkbox within the dialog, the indicator will be displayed as a speedometer-like instrument. The speedometer shows the magnitude of the assigned variable using both a needle gauge and color. In our experience, Lamps do an excellent job of letting users know whether there is a problematic behavior in the model. They also do an excellent job of conserving screen real estate. Speedometer gauges, on the other hand, provide a bit more data to the user at the cost of a larger amount of screen real estate.

Assigning a variable to the Device: To assign a variable to the status indicator, double-click on its name in the Allowable list. Or select the variable name and click the >> button. When you do, the variable will be loaded to the selected list. In addition, as indicated in Figure 6-73, the bottom half of the dialog will become chockablock full of controls and options. You'll use these controls and options to configure the indicator.

Configuring the Indicator: Once you've determined whether to display the indicator as a Lamp or as a speedometer, and you have assigned a variable to the indicator, you need to configure the it. There's lots to do here, but fortunately, the basic process is very straightforward. Here's what you need to do:

- Set the display range for the Status Indicator. Immediately below the allowable list you will see the "Zone Continuum Bar." This bar stretches from the left to the right of the dialog. Below the bar, at its beginning and end, you'll find number boxes that you can use to set the display range for the status indicator. Use these boxes to set minimum and maximum values for the display range. Does the speedometer go from 0 to 140 mph? Or does it go from 10 to 62 mph? In Figure 6-73, the display range has been set from 0 to 20

- Configure each zone. Select a Zone by clicking along the zone continuum bar. When you do, the zone will become highlighted (i.e., will turn black) and the "stakes" at the end(s) of the selected zone will become highlighted. In addition, the numbers in the "Zone begins at" and "Zone ends at" boxes will change to reflect the zone you have selected. Use the numbers to set the boundaries for the selected zone (alternately, drag the stakes to the left or right) Then, use the pop-up Zone Type list to assign Normal (green), Caution (yellow), or Panic (flashing red) to the zone. Assign a sound to the Panic zone if desired.

As you work through the configuration process for each zone, think carefully about the manner in which zones are associated with model performance. For example, low cash values might engender "panic." On the other hand, low levels of toxic waste in groundwater might be a very "green" thing to have while high levels of waste might imply a "panic" display. In setting up status indicator, context is key!

- If desired, associate the Status Indicator with a Switch. In some instances, you may wish for status indicators to "do their thing" only when switched on by the user of the model. For example, indicators that show the magnitude of wolves in the Greater Yellowstone ecosystem may be relevant only after the predators have been introduced into the ecosystem. The optional "On-Off" switch check box gives you this capability. Check the box, and associate the indicator with a switch from the drop-down list. As users interact with your model, when the switch is in the off position the associated indicator will be grayed out.

- Complete the configuration. The remaining controls within the Status Indicator dialog relate to the display of the resultant object on the Interface Layer. Lamps can be configured as small, medium or large in size. Speedometer gauges can display the name of the associated variable, the numeric value associated with the output, and a down-arrow that can take the user directly to the model variable. Finally, retain ending value causes the ending value of the variable to be displayed after the simulation is complete. These different configurations are detailed in Figure 6-75.

Figure 6-75 Status Indicator Display Options