Wednesday, December 13, 2017

Ladder Diagram Design : Flow Diagram Method

Many of systems from input signal are totally random. An example, Elevator control system. In every floor, there is up and down button, also in the elevator, one button for every floor and open/close button. Other than that, there is limit switch on every floor and when elevator pass a floor, it will active, so the control system know the position of elevator. This method is more simple than huffman method, and it more makes sense between length of programs and the needed time.

Example 1.

Condition,

if x1 = 1 then z1 = 1
if x2 = 1 in a moment (after that x2 back to 0) then z1 = 0 and z2 = 1
if z1 = 1 and then x1 = 0, z1 will keep the state 1, and then change the state 0 if x2 is pushed
if x1 = 0 then z2 = 0

The flow diagram,