Lab 6
Prelab


1.    When MOD-8 counter sequences from 0-7, the MUX and DEMUX is connected to each equivalent input
       and output pins with equiavalent numbers.
       The table below shows the explainantions.

 
      From the table, it shows the data selects equivalent number (0-7) will connect to each pin at MUX and
      DEMUX with same number pin. Each pin is the input from the system when door is open which
      connected to MUX.
       At DEMUX, the same pin number as MUX will be connected to give an active low output which
      controlled by the counter.
      From here, when each door is open, the output from DEMUX will cause the system function to alert
      the security.
 

2.    The pin 7 of 74LS151 MUX need to be grounded because it only allow passing input signal to output
       when it is operated under active low condition.

3.    Pin 3 is connected to +5V and pin 2 to ground of 74LS138 DEMUX to enable G1 receive high input
       and G2 a low input for thr DEMUX to operate functionally.
 

Practical Results

 

4.    a) Less wire needed for connection
       b) Utilize or maximize the bandwidth of wire.
       c) Centralized control, easier to check for error.

5.
 

6.    a) Time Division Multiplexing
       b) LAN connection.
       c) Security systems.