Garage Door Opener for ProLogix

Here is the garage door opener example in ProLogix.  This is a fairly simple program.  I'm not going to explain too much here since the code comments explain everything.  In the real world this should have a 5th input for detecting if something is in the way of the door.

*Note: Some of you may be wondering how to know when the door is ajar when their is no door ajar switch.  Just think about it for a bit.  A door ajar is really when door open switch is still closed but closed door switch is still open. :)

Inputs:

1. Open Button
2. Close Button
3. Door Open Switch
4. Door Closed Switch

Outputs:

1. Motor Up
2. Motor Down
3. Door Opening Light
4. Door Closing Light
5. Door Ajar Light

This is a good practice in PLC programming  to assign I/O to internal program variables

The logic for the controls in a Controller

Finally in Main call the subroutines