A Technology pupil has devised a simple model to test his/her programming. The maximum number of people allowed through the entrance for the test run is ten. The program must calculate those entering the park and balance it with those leaving the park. The total number of those in the park must not exceed ten.
The system is switched on.
The total of people in the park is set at 0.
input 1 and 2 are continually checked.
If input 1 detects a person entering the park then 1 is added to the total.
If input 2 detects a person leaving the park 1 is subtracted from the total.
If the total number of people in the park reaches 10 a solenoid locks the entrance turnstile (this stops more people entering the park)
Explain two possible faults/problems with the flow chart.
Explain / describe three possible improvements / additions to the flow chart.
Explain / describe two possible
faults / problems with the flow chart.
1. The flow chart will stop completely when there are ten or more people
in the theme park. It does not continue to check to determine if more
people are leaving and allow more to enter.
2. There is no manual override to the system. There may be a need for a
supervisor to override the system. For example, if the park is full and
there is an accident there will be a need to allow paramedics through the
entrance turnstile. The present flow chart simply locks the entrance.
Explain / describe three ways
in which the flow chart could be improved.
1. Add a loop to the entire flow chart so that it continually works and
checks inputs and especially outputs. The example flow chart simply locks
the entrance turnstile and then stops running. A loop would ensure that
the program continually checks for people leaving the theme park and
allows a subsequent number to enter.
2. Another subroutine needs to be added. This could be called SOLENOID
OFF. Once the number of people in the park drops to below ten the entrance
should start to operate again. The solenoid needs releasing so that the
turnstile will start working again.
3. A new output could be added. A display that shows the total number of
people in the park. This would allow the supervisors to see how many
people they are dealing with. Also, in the event of an emergency the
emergency services could be told the total people in the park, without
delay.