A security system has both a floodlight (very bright light) and an audio alarm.
The data from multiple sensors is analysed and used to:
turn on the floodlight
sound the audio alarm.
Sensors can be used to detect:
if doors are open
the external daylight level
if people are detected within a set distance.
The floodlight (X) and audio alarm (Y) operate according to the following criteria:
Parameter | Description of parameter | Binary value | Condition |
|---|---|---|---|
A | External daylight level | 1 | Low |
0 | High | ||
B | Front door | 1 | Open |
0 | Closed | ||
C | Person is within 2 m | 1 | Detected |
0 | Not detected | ||
D | Back door | 1 | Open |
0 | Closed | ||
E | Security system | 1 | Switched on |
0 | Switched off |
The floodlight turns on (X = 1) if:
the security system is switched on
and
the external daylight level is low
and
a person is detected within 2m.
The audio alarm turns on (Y = 1) if:
the security system is switched on
and
one or more doors are open, or a person is detected within 2m.
Write logic expressions for the security system.
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