Exercise 2 - Constructing a Sequence Diagram
In this exercise, you create two Sequence Diagrams. The 'Sequence Diagram 'REAR_DEFOG_LO_SPEED_NO_LOAD' and Sequence Diagram 'REAR_DEFOG_2HI_SPEED_2LOAD1 figures depict what the diagrams look like at completion of this exercise.
1. Click Graphic Editors from the main Rational Statemate window.
2. Create a Sequence Diagram called REAR_DEFOG_LO_SPEED_NO_LOAD based upon the selections shown in the following figure.
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Type: Sequence Diagram
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Usage: Regular (defaults to this value based upon Type)
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Name Pattern: REAR_DEFOG_LO_SPEED_NO_LOAD
3. Click New from the Open Chart window to create and open a new diagram. The chart is now available for editing.
4. Click Create Partition Line.
5. Draw a Partition Line within the Sequence Diagram. Place the cursor at the location and drag the mouse slightly to the right and release the mouse. This line extends “infinitely.”
6. Click Create External Life Line.
7. Draw two external lifelines in the Sequence Diagram. Place the cursor at the location you want and double-click the mouse. A vertical line extends 'infinitely'. When a lifeline is added to a diagram it is given a default name. To change the names of lifeline, double-click on the text and enter the new name.
8. Name the external lifelines REAR_DEFOG_RELAY and OPERATOR.
9. Click Create Life Line.
10. Draw a lifeline called 'REAR_DEFOG_SS'. This is done the same way as the external lifelines.
11. Click Create Simple Message.
Note: Simple messages have to be drawn between the various lifelines. The following table shows the source and target of each lifeline.
12.
13. Locate the targeted lifeline and place the cursor on the edge of the targeted lifeline, and click to enter the arrowhead.
14. With the Create Simple Message icon still selected, label the messages as shown in the following table - Simple Message Labels.
15. Click Create Message Note to add message notes to the diagram.
16. Select and add the flowing notes to the messages as shown in the following table. The message notes are free text that is associated to particular message lines. Attach the text to the message by clicking on the message line.
1. Customer requests the rear defog system on. 4. After being enabled for Low Speed Max On Time seconds, the rear defog relay is disabled.
17. Click Create Order Insignificant Lineand place this between two of the messages. Between messages 2 and 3, and messages 4 and 5. See the Sequence Diagram 'REAR_DEFOG_LO_SPEED_NO_LOAD figure.
18. Click Create Timing Constraintand add this between message 3 and 4. See the Sequence Diagram 'REAR_DEFOG_LO_SPEED_NO_LOAD figure.
19. Select File > Save from the diagram and then File > Exit.
20. Repeat steps 1-3 to create another sequence diagram called 'REAR_DEFOG_2HI_SPEED_2LOAD1'.
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'LOAD_MONITOR'
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'SPEED_SENSOR'
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'OPERATOR'
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'REAR_DEFOG_RELAY'.
22. Draw a lifeline in the called 'REAR_DEFOG_SS'. This is done in the same manner as was done with the external lifelines.
23. Create simple messages between the various lifelines, based upon the information in the following table, Simple Messages, that show the source and target of each lifeline.
24. Add message notes to the messages within the diagram. Refer to the following table, Message Notes, for the messages that need to be added.
1. Charging subsystem indicates electrical system load. 2. Customer requests the rear defog system to turn on. 5. Vehicle speed increases past the high-speed threshold - the relay can be enabled indefinitely. 6. Load condition one exists, the system starts modulation of the rear defog relay. 7. Modulation starts at the calibrated duty cycle; the relay is disabled.
25. Select File > Save from the diagram and then File > Exit.