Object Oriented PLC for Windows implemented in Delphi 7.0

This is a closer view of my PLC Application where I developed a Object Oriented PLC, the PLC class is a descendent from the TThread Class so you can create Multithreaded PLC's, in this example I control one output with two checkboxes in an anti-tie down logic, the PLC lenguage is Instruction List, here is the plc program:
// ANTI TIE DOWN
LD X000
OR X001
OUT T000 K5
//
{
}
LD X000
AND X001
LD X000
AND X001
ANI T000
OR Y000
ANB
OUT Y000
END
Note: For simulation propuse the PLC Scann runs at 1 sec.
Programacion de PLC, Orientada a Objectos