Question

8) When is it appropriate to use a Signal? Why? Explain Given the following periodic tasks following the format of TaskName(TaskPeriod, TaskExecution Time): TA(40ms, 10ms), TB(120ms, 30ms), TC(80ms, 20ms). 9) Design the cyclic executive for these tasks by listing when each frame starts, what tasks execute and when the execution ends (list idle time too). Frame Starts Tasks Executed Execution Ends

8 and 9 please

Sorry I did a mistake. I just need number 8. About Real Time System

Answer 1

Hey, a very sound question for understanding. Let's start:

Let's understand in brief what is a signal?

The signal is a method of indicating something by the alteration of any quantity. It means in a Real-time system, it's a mode of information exchange between systems through the means of variation in any physical quantities of space and time.

Now, let's focus on the original -problem i.e.,

Real-time systems guarantee the execution of a task within a time T or less i.e., their time constraints are very strict like the airbags system installed in a car. it must detect the collision and open the airbags within a stipulated threshold time value. Thus, making it different from other systems.

When we want to perform certain actions through a set of instruments or devices attached, it is appropriate to use the signal.

For e.g. Considering the same example of the airbags, hence when the collision is detected, the Brake control module(BCM used to signal brakes in electronic control units) should understand these collision signals and take necessary actions like the opening of airbags within a certain threshold of time.

Since signals are random and you should maintain a threshold number signals to process them and take actions. So, it is advisable to first understand the type of signal, minimum samples of signals required for processing and signal processing time within a certain limit.

Thus, when all the above 3 parameters i.e., Signal type, the minimum number of samples and processing time is calculated and it is fulfilling the requirements of our real-time system that it will be executing within the threshold time, it is appropriate to use the signal.

Consider another example,

Suppose an audio converter RTS takes 2.01 seconds to complete the overall process but the threshold value of the execution should be less than 2 seconds. In this case, we can't implement the solution as the necessary characteristics of any RTS is processing any task within a certain threshold time.

I hope it will help.

Thanks and all the best :)

Please don't forget to thumbs up if it helped you.

***************************************COMPLETE************************************