Creating a Vehicle Rear Defogger System : Exercise 2 - Constructing a Sequence Diagram

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.

Sequence Diagram 'REAR_DEFOG_LO_SPEED_NO_LOAD
'

 

Sequence Diagram 'REAR_DEFOG_2HI_SPEED_2LOAD1
'
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.
Note:

Type: Sequence Diagram

Usage: Regular (defaults to this value based upon Type)

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.
Sequence Diagram - Life Lines
11.
Click Create Simple Message.
Note:
12.
13.
Simple Message
 
14.
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.
Simple Message Notes
 
4. After being enabled for Low Speed Max On Time seconds, the rear defog relay is disabled.
17.
Click Create Order Insignificant Line and 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 Constraint and 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.
21.

'LOAD_MONITOR'

'SPEED_SENSOR'

'OPERATOR'

'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.
Simple Messages
 
24.
Note: Labels are not be added to the diagram yet.
Message Notes
 
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.
25.
Select File > Save from the diagram and then File > Exit.