-|---------------|-              -|-------------|-
               X03  |               |           X03  |   Garage    |
Bit Status 1  |   |\|               |     1    |   |\|    Door     |
               ---  |               |           ---  |             |
                    |    Garage     |                |_____________|
                    |     Door      |                
               X04  |               |           X04  
Bit Status 1  |   |\|_______________|     0    |   |\
               ---                              ---  



Open Button  = X00   Top Proximity Sensor    = X03
Close Button = X01   Bottom Proximity Sensor = X04
Stop Button  = X02   Motor Up   = Y0
                     Motor Down = Y1
Open  = V00
Close = V01
Stop  = V02

        V00     X03     V02     V01            Y0
    ---|   |---|   |---| / |---| / |----------(OUT)---
    
        V01     X04     V02     V00            Y1
    ---|   |---| / |---| / |---| / |----------(OUT)---
    
        X02                                    V02
    ---|   |----------------------------------(SET)---
     |          |
     | Y0    Y1 |
     -|  |--|  |-
  
        X00                                    V00
    ---|   |----------------------------------(SET)--- 
                                           |   
                                           |   V01
                                           |--(RST)---
                                           |
                                           |   V02
                                           |--(RST)---

        X01                                    V01
    ---|   |----------------------------------(SET)---
                                           |
                                           |   V00
                                           |--(RST)---
                                           |
                                           |   V02
                                           |--(RST)---
                    _______
   ----------------|  END  |--------------------------
                    -------

 
  There are two things that must happen, the door must close and open.
   The conditions when the door is opening are:
     The door can only open when the top proximity sensor is on, the
     stop variable is off and the door is not closing indicated by the 
     V01 variable
     The door can only close when the bottom proximity sensor is off, the
     stop variable is off and the door is not opening.
   These criteria are attended to in lines 1 and 2. Then we need two put in
   a line to stop the door anywhere, this is done in line 3, there is also
   a by pas line for protection, so that if the sensors fail in any why we
   will not burn out the motor. Line 4 deals with the open button, if it is
   pushed it requests the door to open by setting the V00 variable, and
   resets the close door variable witch stops the door if it is moving down
   and resets the stop variable. Line 5 handles the close button, by requesting
   the door to close in setting the V01 variable, and stops the door by
   resetting the open variable, and also resets the stop variable.